From 675c1056bfe935a2da9be85c3791214e30f2ba24 Mon Sep 17 00:00:00 2001
From: "Jeremy G. Siek" <jsiek@indiana.edu>
Date: Mon, 1 Mar 2021 17:21:21 -0500
Subject: [PATCH] update goldens to match fixes in PR #308 (#321)

---
 executable_semantics/testdata/choice1.golden  | 861 +++++++++++++++++-
 executable_semantics/testdata/fun1.golden     | 158 +++-
 executable_semantics/testdata/fun2.golden     | 296 +++++-
 .../testdata/fun_recur.golden                 | 505 +++++++++-
 executable_semantics/testdata/funptr1.golden  | 266 +++++-
 5 files changed, 2056 insertions(+), 30 deletions(-)

diff --git a/executable_semantics/testdata/choice1.golden b/executable_semantics/testdata/choice1.golden
index a6ff8240cf08..45d5532882c4 100644
--- a/executable_semantics/testdata/choice1.golden
+++ b/executable_semantics/testdata/choice1.golden
@@ -1,7 +1,7 @@
 ********** source program **********
 choice Ints {
 alt None ();
-alt One Int;
+alt One (0 = Int);
 alt Two (0 = Int, 1 = Int);
 }
 fn main () -> Int {
@@ -29,12 +29,14 @@ return n;
 }
 choice MoreInts {
 alt None ();
-alt One Int;
+alt One (0 = Int);
 alt Two (0 = Int, 1 = Int);
 }
 ********** type checking **********
 --- step exp () --->
+--- step exp (0 = Int) --->
 --- step exp Int --->
+--- handle value Int with (0 = Int)<1>(Int,) --->
 --- step exp (0 = Int, 1 = Int) --->
 --- step exp Int --->
 --- handle value Int with (0 = Int, 1 = Int)<1>(Int,) --->
@@ -42,7 +44,9 @@ alt Two (0 = Int, 1 = Int);
 --- handle value Int with (0 = Int, 1 = Int)<2>(Int,Int,) --->
 --- step exp Int --->
 --- step exp () --->
+--- step exp (0 = Int) --->
 --- step exp Int --->
+--- handle value Int with (0 = Int)<1>(Int,) --->
 --- step exp (0 = Int, 1 = Int) --->
 --- step exp Int --->
 --- handle value Int with (0 = Int, 1 = Int)<1>(Int,) --->
@@ -50,7 +54,852 @@ alt Two (0 = Int, 1 = Int);
 --- handle value Int with (0 = Int, 1 = Int)<2>(Int,Int,) --->
 --- step exp Int --->
 --- step exp auto --->
-13: type error in call
-expected: Int
-actual: Tuple(0 = Int)
-EXIT CODE: 255
+--- step exp auto --->
+--- step exp auto --->
+18: compilation error, pattern variables are only allowed in pattern context
+--- step exp auto --->
+20: compilation error, pattern variables are only allowed in pattern context
+--- step exp auto --->
+20: compilation error, pattern variables are only allowed in pattern context
+--- step exp auto --->
+24: compilation error, pattern variables are only allowed in pattern context
+--- step exp auto --->
+28: compilation error, pattern variables are only allowed in pattern context
+--- step exp auto --->
+28: compilation error, pattern variables are only allowed in pattern context
+--- step exp auto --->
+
+********** type checking complete **********
+choice Ints {
+alt None ();
+alt One (0 = Int);
+alt Two (0 = Int, 1 = Int);
+}
+fn main () -> Int {
+var auto: x = Ints.None();
+var auto: y = Ints.One(0 = 42);
+var auto: n = 0;
+match (y) {
+case Ints.None =>
+n = (n + 2);
+case Ints.One(0 = auto: x) =>
+n = ((x + 1) - 42);
+case Ints.Two(0 = auto: a, 1 = auto: b) =>
+n = 2;
+}
+match (x) {
+case Ints.One(0 = auto: x) =>
+n = (x + 2);
+case Ints.None() =>
+n = (n - 1);
+case Ints.Two(0 = auto: x, 1 = auto: y) =>
+n = 5;
+}
+return n;
+}
+choice MoreInts {
+alt None ();
+alt One (0 = Int);
+alt Two (0 = Int, 1 = Int);
+}
+********** starting execution **********
+********** initializing globals **********
+--- step exp () --->
+--- step exp (0 = Int) --->
+--- step exp Int --->
+--- handle value Int with (0 = Int)<1>(Int,) --->
+--- step exp (0 = Int, 1 = Int) --->
+--- step exp Int --->
+--- handle value Int with (0 = Int, 1 = Int)<1>(Int,) --->
+--- step exp Int --->
+--- handle value Int with (0 = Int, 1 = Int)<2>(Int,Int,) --->
+--- step exp () --->
+--- step exp () --->
+--- step exp (0 = Int) --->
+--- step exp Int --->
+--- handle value Int with (0 = Int)<1>(Int,) --->
+--- step exp (0 = Int, 1 = Int) --->
+--- step exp Int --->
+--- handle value Int with (0 = Int, 1 = Int)<1>(Int,) --->
+--- step exp Int --->
+--- handle value Int with (0 = Int, 1 = Int)<2>(Int,Int,) --->
+********** calling main function **********
+{
+stack: top{main()<-1>}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, 
+env: MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp main() --->
+{
+stack: top{main<-1> :: main()<0>}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, 
+env: MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp main --->
+{
+stack: top{fun<main><-1> :: main()<0>}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, 
+env: MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value fun<main> with main()<1>(fun<main>,) --->
+{
+stack: top{()<-1> :: main()<1>(fun<main>,)}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, 
+env: MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp () --->
+{
+stack: top{()<-1> :: main()<1>(fun<main>,)}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, 
+env: MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value () with main()<2>(fun<main>,(),) --->
+pattern_match((), ())
+{
+stack: main{var auto: x = Ints.None(); ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, 
+env: MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step stmt var auto: x = Ints.None(); ...  --->
+{
+stack: main{var auto: x = Ints.None();<-1> :: var auto: y = Ints.One(0 = 42); ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, 
+env: MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step stmt var auto: x = Ints.None(); --->
+{
+stack: main{Ints.None()<-1> :: var auto: x = Ints.None();<0> :: var auto: y = Ints.One(0 = 42); ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, 
+env: MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp Ints.None() --->
+{
+stack: main{Ints.None<-1> :: Ints.None()<0> :: var auto: x = Ints.None();<0> :: var auto: y = Ints.One(0 = 42); ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, 
+env: MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp Ints.None --->
+{
+stack: main{Ints<-1> :: Ints.None<0> :: Ints.None()<0> :: var auto: x = Ints.None();<0> :: var auto: y = Ints.One(0 = 42); ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, 
+env: MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step lvalue Ints --->
+{
+stack: main{ptr<3><-1> :: Ints.None<0> :: Ints.None()<0> :: var auto: x = Ints.None();<0> :: var auto: y = Ints.One(0 = 42); ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, 
+env: MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value ptr<3> with Ints.None<1>(ptr<3>,) --->
+{
+stack: main{Ints.None<-1> :: Ints.None()<0> :: var auto: x = Ints.None();<0> :: var auto: y = Ints.One(0 = 42); ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, 
+env: MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value Ints.None with Ints.None()<1>(Ints.None,) --->
+{
+stack: main{()<-1> :: Ints.None()<1>(Ints.None,) :: var auto: x = Ints.None();<0> :: var auto: y = Ints.One(0 = 42); ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, 
+env: MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp () --->
+{
+stack: main{()<-1> :: Ints.None()<1>(Ints.None,) :: var auto: x = Ints.None();<0> :: var auto: y = Ints.One(0 = 42); ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, 
+env: MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value () with Ints.None()<2>(Ints.None,(),) --->
+{
+stack: main{alt Ints.None ()<-1> :: var auto: x = Ints.None();<0> :: var auto: y = Ints.One(0 = 42); ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, 
+env: MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value alt Ints.None () with var auto: x = Ints.None();<1>(alt Ints.None (),) --->
+{
+stack: main{auto: x<-1> :: var auto: x = Ints.None();<1>(alt Ints.None (),) :: var auto: y = Ints.One(0 = 42); ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, 
+env: MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp auto: x --->
+{
+stack: main{auto<-1> :: auto: x<0> :: var auto: x = Ints.None();<1>(alt Ints.None (),) :: var auto: y = Ints.One(0 = 42); ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, 
+env: MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp auto --->
+{
+stack: main{auto<-1> :: auto: x<0> :: var auto: x = Ints.None();<1>(alt Ints.None (),) :: var auto: y = Ints.One(0 = 42); ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, 
+env: MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value auto with auto: x<1>(auto,) --->
+{
+stack: main{auto: x<-1> :: var auto: x = Ints.None();<1>(alt Ints.None (),) :: var auto: y = Ints.One(0 = 42); ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, 
+env: MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value auto: x with var auto: x = Ints.None();<2>(alt Ints.None (),auto: x,) --->
+pattern_match(auto: x, alt Ints.None ())
+{
+stack: main{var auto: y = Ints.One(0 = 42); ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), 
+env: x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step stmt var auto: y = Ints.One(0 = 42); ...  --->
+{
+stack: main{var auto: y = Ints.One(0 = 42);<-1> :: var auto: n = 0; ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), 
+env: x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step stmt var auto: y = Ints.One(0 = 42); --->
+{
+stack: main{Ints.One(0 = 42)<-1> :: var auto: y = Ints.One(0 = 42);<0> :: var auto: n = 0; ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), 
+env: x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp Ints.One(0 = 42) --->
+{
+stack: main{Ints.One<-1> :: Ints.One(0 = 42)<0> :: var auto: y = Ints.One(0 = 42);<0> :: var auto: n = 0; ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), 
+env: x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp Ints.One --->
+{
+stack: main{Ints<-1> :: Ints.One<0> :: Ints.One(0 = 42)<0> :: var auto: y = Ints.One(0 = 42);<0> :: var auto: n = 0; ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), 
+env: x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step lvalue Ints --->
+{
+stack: main{ptr<3><-1> :: Ints.One<0> :: Ints.One(0 = 42)<0> :: var auto: y = Ints.One(0 = 42);<0> :: var auto: n = 0; ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), 
+env: x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value ptr<3> with Ints.One<1>(ptr<3>,) --->
+{
+stack: main{Ints.One<-1> :: Ints.One(0 = 42)<0> :: var auto: y = Ints.One(0 = 42);<0> :: var auto: n = 0; ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 
+env: x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value Ints.One with Ints.One(0 = 42)<1>(Ints.One,) --->
+{
+stack: main{(0 = 42)<-1> :: Ints.One(0 = 42)<1>(Ints.One,) :: var auto: y = Ints.One(0 = 42);<0> :: var auto: n = 0; ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 
+env: x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp (0 = 42) --->
+{
+stack: main{42<-1> :: (0 = 42)<0> :: Ints.One(0 = 42)<1>(Ints.One,) :: var auto: y = Ints.One(0 = 42);<0> :: var auto: n = 0; ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 
+env: x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp 42 --->
+{
+stack: main{42<-1> :: (0 = 42)<0> :: Ints.One(0 = 42)<1>(Ints.One,) :: var auto: y = Ints.One(0 = 42);<0> :: var auto: n = 0; ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 
+env: x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value 42 with (0 = 42)<1>(42,) --->
+{
+stack: main{(0 = 42@12)<-1> :: Ints.One(0 = 42)<1>(Ints.One,) :: var auto: y = Ints.One(0 = 42);<0> :: var auto: n = 0; ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 
+env: x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value (0 = 42@12) with Ints.One(0 = 42)<2>(Ints.One,(0 = 42@12),) --->
+{
+stack: main{alt Ints.One (0 = 42@13)<-1> :: var auto: y = Ints.One(0 = 42);<0> :: var auto: n = 0; ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 
+env: x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value alt Ints.One (0 = 42@13) with var auto: y = Ints.One(0 = 42);<1>(alt Ints.One (0 = 42@13),) --->
+{
+stack: main{auto: y<-1> :: var auto: y = Ints.One(0 = 42);<1>(alt Ints.One (0 = 42@13),) :: var auto: n = 0; ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 
+env: x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp auto: y --->
+{
+stack: main{auto<-1> :: auto: y<0> :: var auto: y = Ints.One(0 = 42);<1>(alt Ints.One (0 = 42@13),) :: var auto: n = 0; ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 
+env: x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp auto --->
+{
+stack: main{auto<-1> :: auto: y<0> :: var auto: y = Ints.One(0 = 42);<1>(alt Ints.One (0 = 42@13),) :: var auto: n = 0; ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 
+env: x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value auto with auto: y<1>(auto,) --->
+{
+stack: main{auto: y<-1> :: var auto: y = Ints.One(0 = 42);<1>(alt Ints.One (0 = 42@13),) :: var auto: n = 0; ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 
+env: x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value auto: y with var auto: y = Ints.One(0 = 42);<2>(alt Ints.One (0 = 42@13),auto: y,) --->
+pattern_match(auto: y, alt Ints.One (0 = 42@13))
+{
+stack: main{var auto: n = 0; ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 
+env: y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step stmt var auto: n = 0; ...  --->
+{
+stack: main{var auto: n = 0;<-1> :: match (y) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 
+env: y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step stmt var auto: n = 0; --->
+{
+stack: main{0<-1> :: var auto: n = 0;<0> :: match (y) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 
+env: y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp 0 --->
+{
+stack: main{0<-1> :: var auto: n = 0;<0> :: match (y) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 
+env: y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value 0 with var auto: n = 0;<1>(0,) --->
+{
+stack: main{auto: n<-1> :: var auto: n = 0;<1>(0,) :: match (y) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 
+env: y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp auto: n --->
+{
+stack: main{auto<-1> :: auto: n<0> :: var auto: n = 0;<1>(0,) :: match (y) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 
+env: y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp auto --->
+{
+stack: main{auto<-1> :: auto: n<0> :: var auto: n = 0;<1>(0,) :: match (y) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 
+env: y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value auto with auto: n<1>(auto,) --->
+{
+stack: main{auto: n<-1> :: var auto: n = 0;<1>(0,) :: match (y) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 
+env: y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value auto: n with var auto: n = 0;<2>(0,auto: n,) --->
+pattern_match(auto: n, 0)
+{
+stack: main{match (y) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step stmt match (y) {...} ...  --->
+{
+stack: main{match (y) {...}<-1> :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step stmt match (y) {...} --->
+{
+stack: main{y<-1> :: match (y) {...}<0> :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp y --->
+{
+stack: main{alt Ints.One (0 = 42@14)<-1> :: match (y) {...}<0> :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value alt Ints.One (0 = 42@14) with match (y) {...}<1>(alt Ints.One (0 = 42@14),) --->
+{
+stack: main{Ints.None<-1> :: match (y) {...}<1>(alt Ints.One (0 = 42@14),) :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp Ints.None --->
+{
+stack: main{Ints<-1> :: Ints.None<0> :: match (y) {...}<1>(alt Ints.One (0 = 42@14),) :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step lvalue Ints --->
+{
+stack: main{ptr<3><-1> :: Ints.None<0> :: match (y) {...}<1>(alt Ints.One (0 = 42@14),) :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value ptr<3> with Ints.None<1>(ptr<3>,) --->
+{
+stack: main{Ints.None<-1> :: match (y) {...}<1>(alt Ints.One (0 = 42@14),) :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value Ints.None with match (y) {...}<2>(alt Ints.One (0 = 42@14),Ints.None,) --->
+pattern_match(Ints.None, alt Ints.One (0 = 42@14))
+{
+stack: main{Ints.One(0 = auto: x)<-1> :: match (y) {...}<3>(alt Ints.One (0 = 42@14),Ints.None,) :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp Ints.One(0 = auto: x) --->
+{
+stack: main{Ints.One<-1> :: Ints.One(0 = auto: x)<0> :: match (y) {...}<3>(alt Ints.One (0 = 42@14),Ints.None,) :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp Ints.One --->
+{
+stack: main{Ints<-1> :: Ints.One<0> :: Ints.One(0 = auto: x)<0> :: match (y) {...}<3>(alt Ints.One (0 = 42@14),Ints.None,) :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step lvalue Ints --->
+{
+stack: main{ptr<3><-1> :: Ints.One<0> :: Ints.One(0 = auto: x)<0> :: match (y) {...}<3>(alt Ints.One (0 = 42@14),Ints.None,) :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value ptr<3> with Ints.One<1>(ptr<3>,) --->
+{
+stack: main{Ints.One<-1> :: Ints.One(0 = auto: x)<0> :: match (y) {...}<3>(alt Ints.One (0 = 42@14),Ints.None,) :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value Ints.One with Ints.One(0 = auto: x)<1>(Ints.One,) --->
+{
+stack: main{(0 = auto: x)<-1> :: Ints.One(0 = auto: x)<1>(Ints.One,) :: match (y) {...}<3>(alt Ints.One (0 = 42@14),Ints.None,) :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp (0 = auto: x) --->
+{
+stack: main{auto: x<-1> :: (0 = auto: x)<0> :: Ints.One(0 = auto: x)<1>(Ints.One,) :: match (y) {...}<3>(alt Ints.One (0 = 42@14),Ints.None,) :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp auto: x --->
+{
+stack: main{auto<-1> :: auto: x<0> :: (0 = auto: x)<0> :: Ints.One(0 = auto: x)<1>(Ints.One,) :: match (y) {...}<3>(alt Ints.One (0 = 42@14),Ints.None,) :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp auto --->
+{
+stack: main{auto<-1> :: auto: x<0> :: (0 = auto: x)<0> :: Ints.One(0 = auto: x)<1>(Ints.One,) :: match (y) {...}<3>(alt Ints.One (0 = 42@14),Ints.None,) :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value auto with auto: x<1>(auto,) --->
+{
+stack: main{auto: x<-1> :: (0 = auto: x)<0> :: Ints.One(0 = auto: x)<1>(Ints.One,) :: match (y) {...}<3>(alt Ints.One (0 = 42@14),Ints.None,) :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value auto: x with (0 = auto: x)<1>(auto: x,) --->
+{
+stack: main{(0 = auto: x@19)<-1> :: Ints.One(0 = auto: x)<1>(Ints.One,) :: match (y) {...}<3>(alt Ints.One (0 = 42@14),Ints.None,) :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, auto: x, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value (0 = auto: x@19) with Ints.One(0 = auto: x)<2>(Ints.One,(0 = auto: x@19),) --->
+{
+stack: main{alt Ints.One (0 = auto: x@20)<-1> :: match (y) {...}<3>(alt Ints.One (0 = 42@14),Ints.None,) :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, auto: x, auto: x, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value alt Ints.One (0 = auto: x@20) with match (y) {...}<4>(alt Ints.One (0 = 42@14),Ints.None,alt Ints.One (0 = auto: x@20),) --->
+pattern_match(alt Ints.One (0 = auto: x@20), alt Ints.One (0 = 42@14))
+pattern_match((0 = auto: x@20), (0 = 42@14))
+pattern_match(auto: x, 42)
+{
+stack: main{n = ((x + 1) - 42);<-1> :: {
+ ... 
+}
+<0> :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, auto: x, auto: x, 42, 
+env: x: 42, n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step stmt n = ((x + 1) - 42); --->
+{
+stack: main{n<-1> :: n = ((x + 1) - 42);<0> :: {
+ ... 
+}
+<0> :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, auto: x, auto: x, 42, 
+env: x: 42, n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step lvalue n --->
+{
+stack: main{ptr<16><-1> :: n = ((x + 1) - 42);<0> :: {
+ ... 
+}
+<0> :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, auto: x, auto: x, 42, 
+env: x: 42, n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value ptr<16> with n = ((x + 1) - 42);<1>(ptr<16>,) --->
+{
+stack: main{((x + 1) - 42)<-1> :: n = ((x + 1) - 42);<1>(ptr<16>,) :: {
+ ... 
+}
+<0> :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, auto: x, auto: x, 42, 
+env: x: 42, n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp ((x + 1) - 42) --->
+{
+stack: main{(x + 1)<-1> :: ((x + 1) - 42)<0> :: n = ((x + 1) - 42);<1>(ptr<16>,) :: {
+ ... 
+}
+<0> :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, auto: x, auto: x, 42, 
+env: x: 42, n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp (x + 1) --->
+{
+stack: main{x<-1> :: (x + 1)<0> :: ((x + 1) - 42)<0> :: n = ((x + 1) - 42);<1>(ptr<16>,) :: {
+ ... 
+}
+<0> :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, auto: x, auto: x, 42, 
+env: x: 42, n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp x --->
+{
+stack: main{42<-1> :: (x + 1)<0> :: ((x + 1) - 42)<0> :: n = ((x + 1) - 42);<1>(ptr<16>,) :: {
+ ... 
+}
+<0> :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, auto: x, auto: x, 42, 
+env: x: 42, n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value 42 with (x + 1)<1>(42,) --->
+{
+stack: main{1<-1> :: (x + 1)<1>(42,) :: ((x + 1) - 42)<0> :: n = ((x + 1) - 42);<1>(ptr<16>,) :: {
+ ... 
+}
+<0> :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, auto: x, auto: x, 42, 
+env: x: 42, n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp 1 --->
+{
+stack: main{1<-1> :: (x + 1)<1>(42,) :: ((x + 1) - 42)<0> :: n = ((x + 1) - 42);<1>(ptr<16>,) :: {
+ ... 
+}
+<0> :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, auto: x, auto: x, 42, 
+env: x: 42, n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value 1 with (x + 1)<2>(42,1,) --->
+{
+stack: main{43<-1> :: ((x + 1) - 42)<0> :: n = ((x + 1) - 42);<1>(ptr<16>,) :: {
+ ... 
+}
+<0> :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, auto: x, auto: x, 42, 
+env: x: 42, n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value 43 with ((x + 1) - 42)<1>(43,) --->
+{
+stack: main{42<-1> :: ((x + 1) - 42)<1>(43,) :: n = ((x + 1) - 42);<1>(ptr<16>,) :: {
+ ... 
+}
+<0> :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, auto: x, auto: x, 42, 
+env: x: 42, n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp 42 --->
+{
+stack: main{42<-1> :: ((x + 1) - 42)<1>(43,) :: n = ((x + 1) - 42);<1>(ptr<16>,) :: {
+ ... 
+}
+<0> :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, auto: x, auto: x, 42, 
+env: x: 42, n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value 42 with ((x + 1) - 42)<2>(43,42,) --->
+{
+stack: main{1<-1> :: n = ((x + 1) - 42);<1>(ptr<16>,) :: {
+ ... 
+}
+<0> :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, auto: x, auto: x, 42, 
+env: x: 42, n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value 1 with n = ((x + 1) - 42);<2>(ptr<16>,1,) --->
+{
+stack: main{{
+ ... 
+}
+<0> :: match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, 42, 
+env: x: 42, n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step stmt {
+ ... 
+}
+ --->
+{
+stack: main{match (x) {...} ... <-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step stmt match (x) {...} ...  --->
+{
+stack: main{match (x) {...}<-1> :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step stmt match (x) {...} --->
+{
+stack: main{x<-1> :: match (x) {...}<0> :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp x --->
+{
+stack: main{alt Ints.None ()<-1> :: match (x) {...}<0> :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value alt Ints.None () with match (x) {...}<1>(alt Ints.None (),) --->
+{
+stack: main{Ints.One(0 = auto: x)<-1> :: match (x) {...}<1>(alt Ints.None (),) :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp Ints.One(0 = auto: x) --->
+{
+stack: main{Ints.One<-1> :: Ints.One(0 = auto: x)<0> :: match (x) {...}<1>(alt Ints.None (),) :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp Ints.One --->
+{
+stack: main{Ints<-1> :: Ints.One<0> :: Ints.One(0 = auto: x)<0> :: match (x) {...}<1>(alt Ints.None (),) :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step lvalue Ints --->
+{
+stack: main{ptr<3><-1> :: Ints.One<0> :: Ints.One(0 = auto: x)<0> :: match (x) {...}<1>(alt Ints.None (),) :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value ptr<3> with Ints.One<1>(ptr<3>,) --->
+{
+stack: main{Ints.One<-1> :: Ints.One(0 = auto: x)<0> :: match (x) {...}<1>(alt Ints.None (),) :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value Ints.One with Ints.One(0 = auto: x)<1>(Ints.One,) --->
+{
+stack: main{(0 = auto: x)<-1> :: Ints.One(0 = auto: x)<1>(Ints.One,) :: match (x) {...}<1>(alt Ints.None (),) :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp (0 = auto: x) --->
+{
+stack: main{auto: x<-1> :: (0 = auto: x)<0> :: Ints.One(0 = auto: x)<1>(Ints.One,) :: match (x) {...}<1>(alt Ints.None (),) :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp auto: x --->
+{
+stack: main{auto<-1> :: auto: x<0> :: (0 = auto: x)<0> :: Ints.One(0 = auto: x)<1>(Ints.One,) :: match (x) {...}<1>(alt Ints.None (),) :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp auto --->
+{
+stack: main{auto<-1> :: auto: x<0> :: (0 = auto: x)<0> :: Ints.One(0 = auto: x)<1>(Ints.One,) :: match (x) {...}<1>(alt Ints.None (),) :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value auto with auto: x<1>(auto,) --->
+{
+stack: main{auto: x<-1> :: (0 = auto: x)<0> :: Ints.One(0 = auto: x)<1>(Ints.One,) :: match (x) {...}<1>(alt Ints.None (),) :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value auto: x with (0 = auto: x)<1>(auto: x,) --->
+{
+stack: main{(0 = auto: x@23)<-1> :: Ints.One(0 = auto: x)<1>(Ints.One,) :: match (x) {...}<1>(alt Ints.None (),) :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value (0 = auto: x@23) with Ints.One(0 = auto: x)<2>(Ints.One,(0 = auto: x@23),) --->
+{
+stack: main{alt Ints.One (0 = auto: x@24)<-1> :: match (x) {...}<1>(alt Ints.None (),) :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, auto: x, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value alt Ints.One (0 = auto: x@24) with match (x) {...}<2>(alt Ints.None (),alt Ints.One (0 = auto: x@24),) --->
+pattern_match(alt Ints.One (0 = auto: x@24), alt Ints.None ())
+{
+stack: main{Ints.None()<-1> :: match (x) {...}<3>(alt Ints.None (),alt Ints.One (0 = auto: x@24),) :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, auto: x, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp Ints.None() --->
+{
+stack: main{Ints.None<-1> :: Ints.None()<0> :: match (x) {...}<3>(alt Ints.None (),alt Ints.One (0 = auto: x@24),) :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, auto: x, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp Ints.None --->
+{
+stack: main{Ints<-1> :: Ints.None<0> :: Ints.None()<0> :: match (x) {...}<3>(alt Ints.None (),alt Ints.One (0 = auto: x@24),) :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, auto: x, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step lvalue Ints --->
+{
+stack: main{ptr<3><-1> :: Ints.None<0> :: Ints.None()<0> :: match (x) {...}<3>(alt Ints.None (),alt Ints.One (0 = auto: x@24),) :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, auto: x, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value ptr<3> with Ints.None<1>(ptr<3>,) --->
+{
+stack: main{Ints.None<-1> :: Ints.None()<0> :: match (x) {...}<3>(alt Ints.None (),alt Ints.One (0 = auto: x@24),) :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, auto: x, Ints.None, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value Ints.None with Ints.None()<1>(Ints.None,) --->
+{
+stack: main{()<-1> :: Ints.None()<1>(Ints.None,) :: match (x) {...}<3>(alt Ints.None (),alt Ints.One (0 = auto: x@24),) :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, auto: x, Ints.None, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp () --->
+{
+stack: main{()<-1> :: Ints.None()<1>(Ints.None,) :: match (x) {...}<3>(alt Ints.None (),alt Ints.One (0 = auto: x@24),) :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, auto: x, Ints.None, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value () with Ints.None()<2>(Ints.None,(),) --->
+{
+stack: main{alt Ints.None ()<-1> :: match (x) {...}<3>(alt Ints.None (),alt Ints.One (0 = auto: x@24),) :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, auto: x, Ints.None, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value alt Ints.None () with match (x) {...}<4>(alt Ints.None (),alt Ints.One (0 = auto: x@24),alt Ints.None (),) --->
+pattern_match(alt Ints.None (), alt Ints.None ())
+pattern_match((), ())
+{
+stack: main{n = (n - 1);<-1> :: {
+ ... 
+}
+<0> :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, auto: x, Ints.None, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step stmt n = (n - 1); --->
+{
+stack: main{n<-1> :: n = (n - 1);<0> :: {
+ ... 
+}
+<0> :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, auto: x, Ints.None, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step lvalue n --->
+{
+stack: main{ptr<16><-1> :: n = (n - 1);<0> :: {
+ ... 
+}
+<0> :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, auto: x, Ints.None, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value ptr<16> with n = (n - 1);<1>(ptr<16>,) --->
+{
+stack: main{(n - 1)<-1> :: n = (n - 1);<1>(ptr<16>,) :: {
+ ... 
+}
+<0> :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, auto: x, Ints.None, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp (n - 1) --->
+{
+stack: main{n<-1> :: (n - 1)<0> :: n = (n - 1);<1>(ptr<16>,) :: {
+ ... 
+}
+<0> :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, auto: x, Ints.None, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp n --->
+{
+stack: main{1<-1> :: (n - 1)<0> :: n = (n - 1);<1>(ptr<16>,) :: {
+ ... 
+}
+<0> :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, auto: x, Ints.None, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value 1 with (n - 1)<1>(1,) --->
+{
+stack: main{1<-1> :: (n - 1)<1>(1,) :: n = (n - 1);<1>(ptr<16>,) :: {
+ ... 
+}
+<0> :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, auto: x, Ints.None, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp 1 --->
+{
+stack: main{1<-1> :: (n - 1)<1>(1,) :: n = (n - 1);<1>(ptr<16>,) :: {
+ ... 
+}
+<0> :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, auto: x, Ints.None, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value 1 with (n - 1)<2>(1,1,) --->
+{
+stack: main{0<-1> :: n = (n - 1);<1>(ptr<16>,) :: {
+ ... 
+}
+<0> :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 1, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, auto: x, Ints.None, 
+env: n: 1, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value 0 with n = (n - 1);<2>(ptr<16>,0,) --->
+{
+stack: main{{
+ ... 
+}
+<0> :: return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, auto: x, Ints.None, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step stmt {
+ ... 
+}
+ --->
+{
+stack: main{return n;<-1>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, auto: x, Ints.None, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step stmt return n; --->
+{
+stack: main{n<-1> :: return n;<0>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, auto: x, Ints.None, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- step exp n --->
+{
+stack: main{0<-1> :: return n;<0>} :: top{}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, alt Ints.None (), Ints.One, 42, 42, 42, alt Ints.One (0 = 42@14), 0, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, auto: x, Ints.None, 
+env: n: 0, y: alt Ints.One (0 = 42@14), x: alt Ints.None (), MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+--- handle value 0 with return n;<1>(0,) --->
+{
+stack: top{0<-1>}
+heap: Int, Int, Int, choice Ints, fun<main>, Int, Int, Int, choice MoreInts, Ints.None, !!alt Ints.None !!(), Ints.One, 42, 42, !!42, !!alt Ints.One !!(0 = !!42@14), !!0, Ints.None, Ints.One, auto: x, auto: x, !!42, Ints.One, auto: x, auto: x, Ints.None, 
+env: MoreInts: choice MoreInts, main: fun<main>, Ints: choice Ints, 
+}
+result: 0
diff --git a/executable_semantics/testdata/fun1.golden b/executable_semantics/testdata/fun1.golden
index f1f18d2ba160..77b895e21ce0 100644
--- a/executable_semantics/testdata/fun1.golden
+++ b/executable_semantics/testdata/fun1.golden
@@ -1,5 +1,5 @@
 ********** source program **********
-fn f Int: x -> Int {
+fn f (0 = Int: x) -> Int {
 return (x - 1);
 
 }
@@ -14,7 +14,155 @@ return f(0 = 1);
 --- step exp Int --->
 --- step exp Int --->
 --- step exp Int --->
-10: type error in call
-expected: Int
-actual: Tuple(0 = Int)
-EXIT CODE: 255
+
+********** type checking complete **********
+fn f (0 = Int: x) -> Int {
+return (x - 1);
+}
+fn main () -> Int {
+return f(0 = 1);
+}
+********** starting execution **********
+********** initializing globals **********
+--- step exp (0 = Int: x) --->
+--- step exp Int: x --->
+--- step exp Int --->
+--- handle value Int with Int: x<1>(Int,) --->
+--- handle value Int: x with (0 = Int: x)<1>(Int: x,) --->
+--- step exp () --->
+********** calling main function **********
+{
+stack: top{main()<-1>}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step exp main() --->
+{
+stack: top{main<-1> :: main()<0>}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step exp main --->
+{
+stack: top{fun<main><-1> :: main()<0>}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- handle value fun<main> with main()<1>(fun<main>,) --->
+{
+stack: top{()<-1> :: main()<1>(fun<main>,)}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step exp () --->
+{
+stack: top{()<-1> :: main()<1>(fun<main>,)}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- handle value () with main()<2>(fun<main>,(),) --->
+pattern_match((), ())
+{
+stack: main{return f(0 = 1);<-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step stmt return f(0 = 1); --->
+{
+stack: main{f(0 = 1)<-1> :: return f(0 = 1);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step exp f(0 = 1) --->
+{
+stack: main{f<-1> :: f(0 = 1)<0> :: return f(0 = 1);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step exp f --->
+{
+stack: main{fun<f><-1> :: f(0 = 1)<0> :: return f(0 = 1);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- handle value fun<f> with f(0 = 1)<1>(fun<f>,) --->
+{
+stack: main{(0 = 1)<-1> :: f(0 = 1)<1>(fun<f>,) :: return f(0 = 1);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step exp (0 = 1) --->
+{
+stack: main{1<-1> :: (0 = 1)<0> :: f(0 = 1)<1>(fun<f>,) :: return f(0 = 1);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step exp 1 --->
+{
+stack: main{1<-1> :: (0 = 1)<0> :: f(0 = 1)<1>(fun<f>,) :: return f(0 = 1);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- handle value 1 with (0 = 1)<1>(1,) --->
+{
+stack: main{(0 = 1@3)<-1> :: f(0 = 1)<1>(fun<f>,) :: return f(0 = 1);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 1, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- handle value (0 = 1@3) with f(0 = 1)<2>(fun<f>,(0 = 1@3),) --->
+pattern_match((0 = Int: x@0), (0 = 1@3))
+pattern_match(Int: x, 1)
+{
+stack: f{return (x - 1);<-1>} :: main{return f(0 = 1);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- step stmt return (x - 1); --->
+{
+stack: f{(x - 1)<-1> :: return (x - 1);<0>} :: main{return f(0 = 1);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- step exp (x - 1) --->
+{
+stack: f{x<-1> :: (x - 1)<0> :: return (x - 1);<0>} :: main{return f(0 = 1);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- step exp x --->
+{
+stack: f{1<-1> :: (x - 1)<0> :: return (x - 1);<0>} :: main{return f(0 = 1);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- handle value 1 with (x - 1)<1>(1,) --->
+{
+stack: f{1<-1> :: (x - 1)<1>(1,) :: return (x - 1);<0>} :: main{return f(0 = 1);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- step exp 1 --->
+{
+stack: f{1<-1> :: (x - 1)<1>(1,) :: return (x - 1);<0>} :: main{return f(0 = 1);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- handle value 1 with (x - 1)<2>(1,1,) --->
+{
+stack: f{0<-1> :: return (x - 1);<0>} :: main{return f(0 = 1);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- handle value 0 with return (x - 1);<1>(0,) --->
+{
+stack: main{0<-1> :: return f(0 = 1);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 1, !!1, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- handle value 0 with return f(0 = 1);<1>(0,) --->
+{
+stack: top{0<-1>}
+heap: Int: x, fun<f>, fun<main>, 1, !!1, 
+env: main: fun<main>, f: fun<f>, 
+}
+result: 0
diff --git a/executable_semantics/testdata/fun2.golden b/executable_semantics/testdata/fun2.golden
index 9c440fa9482c..421e6ce5f9c2 100644
--- a/executable_semantics/testdata/fun2.golden
+++ b/executable_semantics/testdata/fun2.golden
@@ -1,5 +1,5 @@
 ********** source program **********
-fn f Int: x -> Int {
+fn f (0 = Int: x) -> Int {
 return 0;
 
 }
@@ -20,7 +20,293 @@ return b;
 --- step exp Int --->
 --- step exp Int --->
 --- step exp Int --->
-15: type error in call
-expected: Int
-actual: Tuple(0 = Int)
-EXIT CODE: 255
+
+********** type checking complete **********
+fn f (0 = Int: x) -> Int {
+return 0;
+}
+fn main () -> Int {
+var Int: a = 0;
+var Int: b = 1;
+f(0 = a);
+b = a;
+return b;
+}
+********** starting execution **********
+********** initializing globals **********
+--- step exp (0 = Int: x) --->
+--- step exp Int: x --->
+--- step exp Int --->
+--- handle value Int with Int: x<1>(Int,) --->
+--- handle value Int: x with (0 = Int: x)<1>(Int: x,) --->
+--- step exp () --->
+********** calling main function **********
+{
+stack: top{main()<-1>}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step exp main() --->
+{
+stack: top{main<-1> :: main()<0>}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step exp main --->
+{
+stack: top{fun<main><-1> :: main()<0>}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- handle value fun<main> with main()<1>(fun<main>,) --->
+{
+stack: top{()<-1> :: main()<1>(fun<main>,)}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step exp () --->
+{
+stack: top{()<-1> :: main()<1>(fun<main>,)}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- handle value () with main()<2>(fun<main>,(),) --->
+pattern_match((), ())
+{
+stack: main{var Int: a = 0; ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step stmt var Int: a = 0; ...  --->
+{
+stack: main{var Int: a = 0;<-1> :: var Int: b = 1; ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step stmt var Int: a = 0; --->
+{
+stack: main{0<-1> :: var Int: a = 0;<0> :: var Int: b = 1; ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step exp 0 --->
+{
+stack: main{0<-1> :: var Int: a = 0;<0> :: var Int: b = 1; ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- handle value 0 with var Int: a = 0;<1>(0,) --->
+{
+stack: main{Int: a<-1> :: var Int: a = 0;<1>(0,) :: var Int: b = 1; ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step exp Int: a --->
+{
+stack: main{Int<-1> :: Int: a<0> :: var Int: a = 0;<1>(0,) :: var Int: b = 1; ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step exp Int --->
+{
+stack: main{Int<-1> :: Int: a<0> :: var Int: a = 0;<1>(0,) :: var Int: b = 1; ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- handle value Int with Int: a<1>(Int,) --->
+{
+stack: main{Int: a<-1> :: var Int: a = 0;<1>(0,) :: var Int: b = 1; ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- handle value Int: a with var Int: a = 0;<2>(0,Int: a,) --->
+pattern_match(Int: a, 0)
+{
+stack: main{var Int: b = 1; ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 
+env: a: 0, main: fun<main>, f: fun<f>, 
+}
+--- step stmt var Int: b = 1; ...  --->
+{
+stack: main{var Int: b = 1;<-1> :: f(0 = a); ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 
+env: a: 0, main: fun<main>, f: fun<f>, 
+}
+--- step stmt var Int: b = 1; --->
+{
+stack: main{1<-1> :: var Int: b = 1;<0> :: f(0 = a); ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 
+env: a: 0, main: fun<main>, f: fun<f>, 
+}
+--- step exp 1 --->
+{
+stack: main{1<-1> :: var Int: b = 1;<0> :: f(0 = a); ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 
+env: a: 0, main: fun<main>, f: fun<f>, 
+}
+--- handle value 1 with var Int: b = 1;<1>(1,) --->
+{
+stack: main{Int: b<-1> :: var Int: b = 1;<1>(1,) :: f(0 = a); ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 
+env: a: 0, main: fun<main>, f: fun<f>, 
+}
+--- step exp Int: b --->
+{
+stack: main{Int<-1> :: Int: b<0> :: var Int: b = 1;<1>(1,) :: f(0 = a); ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 
+env: a: 0, main: fun<main>, f: fun<f>, 
+}
+--- step exp Int --->
+{
+stack: main{Int<-1> :: Int: b<0> :: var Int: b = 1;<1>(1,) :: f(0 = a); ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 
+env: a: 0, main: fun<main>, f: fun<f>, 
+}
+--- handle value Int with Int: b<1>(Int,) --->
+{
+stack: main{Int: b<-1> :: var Int: b = 1;<1>(1,) :: f(0 = a); ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 
+env: a: 0, main: fun<main>, f: fun<f>, 
+}
+--- handle value Int: b with var Int: b = 1;<2>(1,Int: b,) --->
+pattern_match(Int: b, 1)
+{
+stack: main{f(0 = a); ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 1, 
+env: b: 1, a: 0, main: fun<main>, f: fun<f>, 
+}
+--- step stmt f(0 = a); ...  --->
+{
+stack: main{f(0 = a);<-1> :: b = a; ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 1, 
+env: b: 1, a: 0, main: fun<main>, f: fun<f>, 
+}
+--- step stmt f(0 = a); --->
+{
+stack: main{f(0 = a)<-1> :: f(0 = a);<-1> :: b = a; ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 1, 
+env: b: 1, a: 0, main: fun<main>, f: fun<f>, 
+}
+--- step exp f(0 = a) --->
+{
+stack: main{f<-1> :: f(0 = a)<0> :: f(0 = a);<-1> :: b = a; ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 1, 
+env: b: 1, a: 0, main: fun<main>, f: fun<f>, 
+}
+--- step exp f --->
+{
+stack: main{fun<f><-1> :: f(0 = a)<0> :: f(0 = a);<-1> :: b = a; ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 1, 
+env: b: 1, a: 0, main: fun<main>, f: fun<f>, 
+}
+--- handle value fun<f> with f(0 = a)<1>(fun<f>,) --->
+{
+stack: main{(0 = a)<-1> :: f(0 = a)<1>(fun<f>,) :: f(0 = a);<-1> :: b = a; ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 1, 
+env: b: 1, a: 0, main: fun<main>, f: fun<f>, 
+}
+--- step exp (0 = a) --->
+{
+stack: main{a<-1> :: (0 = a)<0> :: f(0 = a)<1>(fun<f>,) :: f(0 = a);<-1> :: b = a; ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 1, 
+env: b: 1, a: 0, main: fun<main>, f: fun<f>, 
+}
+--- step exp a --->
+{
+stack: main{0<-1> :: (0 = a)<0> :: f(0 = a)<1>(fun<f>,) :: f(0 = a);<-1> :: b = a; ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 1, 
+env: b: 1, a: 0, main: fun<main>, f: fun<f>, 
+}
+--- handle value 0 with (0 = a)<1>(0,) --->
+{
+stack: main{(0 = 0@5)<-1> :: f(0 = a)<1>(fun<f>,) :: f(0 = a);<-1> :: b = a; ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 1, 0, 
+env: b: 1, a: 0, main: fun<main>, f: fun<f>, 
+}
+--- handle value (0 = 0@5) with f(0 = a)<2>(fun<f>,(0 = 0@5),) --->
+pattern_match((0 = Int: x@0), (0 = 0@5))
+pattern_match(Int: x, 0)
+{
+stack: f{return 0;<-1>} :: main{f(0 = a);<-1> :: b = a; ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 1, 0, 0, 
+env: x: 0, main: fun<main>, f: fun<f>, 
+}
+--- step stmt return 0; --->
+{
+stack: f{0<-1> :: return 0;<0>} :: main{f(0 = a);<-1> :: b = a; ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 1, 0, 0, 
+env: x: 0, main: fun<main>, f: fun<f>, 
+}
+--- step exp 0 --->
+{
+stack: f{0<-1> :: return 0;<0>} :: main{f(0 = a);<-1> :: b = a; ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 1, 0, 0, 
+env: x: 0, main: fun<main>, f: fun<f>, 
+}
+--- handle value 0 with return 0;<1>(0,) --->
+{
+stack: main{0<-1> :: f(0 = a);<-1> :: b = a; ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 1, 0, !!0, 
+env: b: 1, a: 0, main: fun<main>, f: fun<f>, 
+}
+--- handle value 0 with f(0 = a);<0>(0,) --->
+{
+stack: main{b = a; ... <-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 1, 0, !!0, 
+env: b: 1, a: 0, main: fun<main>, f: fun<f>, 
+}
+--- step stmt b = a; ...  --->
+{
+stack: main{b = a;<-1> :: return b;<-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 1, 0, !!0, 
+env: b: 1, a: 0, main: fun<main>, f: fun<f>, 
+}
+--- step stmt b = a; --->
+{
+stack: main{b<-1> :: b = a;<0> :: return b;<-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 1, 0, !!0, 
+env: b: 1, a: 0, main: fun<main>, f: fun<f>, 
+}
+--- step lvalue b --->
+{
+stack: main{ptr<4><-1> :: b = a;<0> :: return b;<-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 1, 0, !!0, 
+env: b: 1, a: 0, main: fun<main>, f: fun<f>, 
+}
+--- handle value ptr<4> with b = a;<1>(ptr<4>,) --->
+{
+stack: main{a<-1> :: b = a;<1>(ptr<4>,) :: return b;<-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 1, 0, !!0, 
+env: b: 1, a: 0, main: fun<main>, f: fun<f>, 
+}
+--- step exp a --->
+{
+stack: main{0<-1> :: b = a;<1>(ptr<4>,) :: return b;<-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 1, 0, !!0, 
+env: b: 1, a: 0, main: fun<main>, f: fun<f>, 
+}
+--- handle value 0 with b = a;<2>(ptr<4>,0,) --->
+{
+stack: main{return b;<-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 0, 0, !!0, 
+env: b: 0, a: 0, main: fun<main>, f: fun<f>, 
+}
+--- step stmt return b; --->
+{
+stack: main{b<-1> :: return b;<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 0, 0, !!0, 
+env: b: 0, a: 0, main: fun<main>, f: fun<f>, 
+}
+--- step exp b --->
+{
+stack: main{0<-1> :: return b;<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 0, 0, 0, !!0, 
+env: b: 0, a: 0, main: fun<main>, f: fun<f>, 
+}
+--- handle value 0 with return b;<1>(0,) --->
+{
+stack: top{0<-1>}
+heap: Int: x, fun<f>, fun<main>, !!0, !!0, !!0, !!0, 
+env: main: fun<main>, f: fun<f>, 
+}
+result: 0
diff --git a/executable_semantics/testdata/fun_recur.golden b/executable_semantics/testdata/fun_recur.golden
index 783bf684ae0c..d305571cd5fa 100644
--- a/executable_semantics/testdata/fun_recur.golden
+++ b/executable_semantics/testdata/fun_recur.golden
@@ -1,5 +1,5 @@
 ********** source program **********
-fn f Int: x -> Int {
+fn f (0 = Int: x) -> Int {
 if ((x == 0))
 return x;
 else
@@ -16,7 +16,502 @@ return f(0 = 2);
 --- step exp Int --->
 --- step exp Int --->
 --- step exp Int --->
-9: type error in call
-expected: Int
-actual: Tuple(0 = Int)
-EXIT CODE: 255
+--- step exp Int --->
+
+********** type checking complete **********
+fn f (0 = Int: x) -> Int {
+if ((x == 0))
+return x;
+else
+return f(0 = (x - 1));
+}
+fn main () -> Int {
+return f(0 = 2);
+}
+********** starting execution **********
+********** initializing globals **********
+--- step exp (0 = Int: x) --->
+--- step exp Int: x --->
+--- step exp Int --->
+--- handle value Int with Int: x<1>(Int,) --->
+--- handle value Int: x with (0 = Int: x)<1>(Int: x,) --->
+--- step exp () --->
+********** calling main function **********
+{
+stack: top{main()<-1>}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step exp main() --->
+{
+stack: top{main<-1> :: main()<0>}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step exp main --->
+{
+stack: top{fun<main><-1> :: main()<0>}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- handle value fun<main> with main()<1>(fun<main>,) --->
+{
+stack: top{()<-1> :: main()<1>(fun<main>,)}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step exp () --->
+{
+stack: top{()<-1> :: main()<1>(fun<main>,)}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- handle value () with main()<2>(fun<main>,(),) --->
+pattern_match((), ())
+{
+stack: main{return f(0 = 2);<-1>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step stmt return f(0 = 2); --->
+{
+stack: main{f(0 = 2)<-1> :: return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step exp f(0 = 2) --->
+{
+stack: main{f<-1> :: f(0 = 2)<0> :: return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step exp f --->
+{
+stack: main{fun<f><-1> :: f(0 = 2)<0> :: return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- handle value fun<f> with f(0 = 2)<1>(fun<f>,) --->
+{
+stack: main{(0 = 2)<-1> :: f(0 = 2)<1>(fun<f>,) :: return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step exp (0 = 2) --->
+{
+stack: main{2<-1> :: (0 = 2)<0> :: f(0 = 2)<1>(fun<f>,) :: return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- step exp 2 --->
+{
+stack: main{2<-1> :: (0 = 2)<0> :: f(0 = 2)<1>(fun<f>,) :: return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- handle value 2 with (0 = 2)<1>(2,) --->
+{
+stack: main{(0 = 2@3)<-1> :: f(0 = 2)<1>(fun<f>,) :: return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- handle value (0 = 2@3) with f(0 = 2)<2>(fun<f>,(0 = 2@3),) --->
+pattern_match((0 = Int: x@0), (0 = 2@3))
+pattern_match(Int: x, 2)
+{
+stack: f{if ((x == 0))
+ ... 
+else
+ ... <-1>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 
+env: x: 2, main: fun<main>, f: fun<f>, 
+}
+--- step stmt if ((x == 0))
+ ... 
+else
+ ...  --->
+{
+stack: f{(x == 0)<-1> :: if ((x == 0))
+ ... 
+else
+ ... <0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 
+env: x: 2, main: fun<main>, f: fun<f>, 
+}
+--- step exp (x == 0) --->
+{
+stack: f{x<-1> :: (x == 0)<0> :: if ((x == 0))
+ ... 
+else
+ ... <0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 
+env: x: 2, main: fun<main>, f: fun<f>, 
+}
+--- step exp x --->
+{
+stack: f{2<-1> :: (x == 0)<0> :: if ((x == 0))
+ ... 
+else
+ ... <0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 
+env: x: 2, main: fun<main>, f: fun<f>, 
+}
+--- handle value 2 with (x == 0)<1>(2,) --->
+{
+stack: f{0<-1> :: (x == 0)<1>(2,) :: if ((x == 0))
+ ... 
+else
+ ... <0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 
+env: x: 2, main: fun<main>, f: fun<f>, 
+}
+--- step exp 0 --->
+{
+stack: f{0<-1> :: (x == 0)<1>(2,) :: if ((x == 0))
+ ... 
+else
+ ... <0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 
+env: x: 2, main: fun<main>, f: fun<f>, 
+}
+--- handle value 0 with (x == 0)<2>(2,0,) --->
+{
+stack: f{false<-1> :: if ((x == 0))
+ ... 
+else
+ ... <0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 
+env: x: 2, main: fun<main>, f: fun<f>, 
+}
+--- handle value false with if ((x == 0))
+ ... 
+else
+ ... <1>(false,) --->
+{
+stack: f{return f(0 = (x - 1));<-1>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 
+env: x: 2, main: fun<main>, f: fun<f>, 
+}
+--- step stmt return f(0 = (x - 1)); --->
+{
+stack: f{f(0 = (x - 1))<-1> :: return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 
+env: x: 2, main: fun<main>, f: fun<f>, 
+}
+--- step exp f(0 = (x - 1)) --->
+{
+stack: f{f<-1> :: f(0 = (x - 1))<0> :: return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 
+env: x: 2, main: fun<main>, f: fun<f>, 
+}
+--- step exp f --->
+{
+stack: f{fun<f><-1> :: f(0 = (x - 1))<0> :: return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 
+env: x: 2, main: fun<main>, f: fun<f>, 
+}
+--- handle value fun<f> with f(0 = (x - 1))<1>(fun<f>,) --->
+{
+stack: f{(0 = (x - 1))<-1> :: f(0 = (x - 1))<1>(fun<f>,) :: return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 
+env: x: 2, main: fun<main>, f: fun<f>, 
+}
+--- step exp (0 = (x - 1)) --->
+{
+stack: f{(x - 1)<-1> :: (0 = (x - 1))<0> :: f(0 = (x - 1))<1>(fun<f>,) :: return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 
+env: x: 2, main: fun<main>, f: fun<f>, 
+}
+--- step exp (x - 1) --->
+{
+stack: f{x<-1> :: (x - 1)<0> :: (0 = (x - 1))<0> :: f(0 = (x - 1))<1>(fun<f>,) :: return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 
+env: x: 2, main: fun<main>, f: fun<f>, 
+}
+--- step exp x --->
+{
+stack: f{2<-1> :: (x - 1)<0> :: (0 = (x - 1))<0> :: f(0 = (x - 1))<1>(fun<f>,) :: return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 
+env: x: 2, main: fun<main>, f: fun<f>, 
+}
+--- handle value 2 with (x - 1)<1>(2,) --->
+{
+stack: f{1<-1> :: (x - 1)<1>(2,) :: (0 = (x - 1))<0> :: f(0 = (x - 1))<1>(fun<f>,) :: return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 
+env: x: 2, main: fun<main>, f: fun<f>, 
+}
+--- step exp 1 --->
+{
+stack: f{1<-1> :: (x - 1)<1>(2,) :: (0 = (x - 1))<0> :: f(0 = (x - 1))<1>(fun<f>,) :: return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 
+env: x: 2, main: fun<main>, f: fun<f>, 
+}
+--- handle value 1 with (x - 1)<2>(2,1,) --->
+{
+stack: f{1<-1> :: (0 = (x - 1))<0> :: f(0 = (x - 1))<1>(fun<f>,) :: return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 
+env: x: 2, main: fun<main>, f: fun<f>, 
+}
+--- handle value 1 with (0 = (x - 1))<1>(1,) --->
+{
+stack: f{(0 = 1@5)<-1> :: f(0 = (x - 1))<1>(fun<f>,) :: return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 
+env: x: 2, main: fun<main>, f: fun<f>, 
+}
+--- handle value (0 = 1@5) with f(0 = (x - 1))<2>(fun<f>,(0 = 1@5),) --->
+pattern_match((0 = Int: x@0), (0 = 1@5))
+pattern_match(Int: x, 1)
+{
+stack: f{if ((x == 0))
+ ... 
+else
+ ... <-1>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- step stmt if ((x == 0))
+ ... 
+else
+ ...  --->
+{
+stack: f{(x == 0)<-1> :: if ((x == 0))
+ ... 
+else
+ ... <0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- step exp (x == 0) --->
+{
+stack: f{x<-1> :: (x == 0)<0> :: if ((x == 0))
+ ... 
+else
+ ... <0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- step exp x --->
+{
+stack: f{1<-1> :: (x == 0)<0> :: if ((x == 0))
+ ... 
+else
+ ... <0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- handle value 1 with (x == 0)<1>(1,) --->
+{
+stack: f{0<-1> :: (x == 0)<1>(1,) :: if ((x == 0))
+ ... 
+else
+ ... <0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- step exp 0 --->
+{
+stack: f{0<-1> :: (x == 0)<1>(1,) :: if ((x == 0))
+ ... 
+else
+ ... <0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- handle value 0 with (x == 0)<2>(1,0,) --->
+{
+stack: f{false<-1> :: if ((x == 0))
+ ... 
+else
+ ... <0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- handle value false with if ((x == 0))
+ ... 
+else
+ ... <1>(false,) --->
+{
+stack: f{return f(0 = (x - 1));<-1>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- step stmt return f(0 = (x - 1)); --->
+{
+stack: f{f(0 = (x - 1))<-1> :: return f(0 = (x - 1));<0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- step exp f(0 = (x - 1)) --->
+{
+stack: f{f<-1> :: f(0 = (x - 1))<0> :: return f(0 = (x - 1));<0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- step exp f --->
+{
+stack: f{fun<f><-1> :: f(0 = (x - 1))<0> :: return f(0 = (x - 1));<0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- handle value fun<f> with f(0 = (x - 1))<1>(fun<f>,) --->
+{
+stack: f{(0 = (x - 1))<-1> :: f(0 = (x - 1))<1>(fun<f>,) :: return f(0 = (x - 1));<0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- step exp (0 = (x - 1)) --->
+{
+stack: f{(x - 1)<-1> :: (0 = (x - 1))<0> :: f(0 = (x - 1))<1>(fun<f>,) :: return f(0 = (x - 1));<0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- step exp (x - 1) --->
+{
+stack: f{x<-1> :: (x - 1)<0> :: (0 = (x - 1))<0> :: f(0 = (x - 1))<1>(fun<f>,) :: return f(0 = (x - 1));<0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- step exp x --->
+{
+stack: f{1<-1> :: (x - 1)<0> :: (0 = (x - 1))<0> :: f(0 = (x - 1))<1>(fun<f>,) :: return f(0 = (x - 1));<0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- handle value 1 with (x - 1)<1>(1,) --->
+{
+stack: f{1<-1> :: (x - 1)<1>(1,) :: (0 = (x - 1))<0> :: f(0 = (x - 1))<1>(fun<f>,) :: return f(0 = (x - 1));<0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- step exp 1 --->
+{
+stack: f{1<-1> :: (x - 1)<1>(1,) :: (0 = (x - 1))<0> :: f(0 = (x - 1))<1>(fun<f>,) :: return f(0 = (x - 1));<0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- handle value 1 with (x - 1)<2>(1,1,) --->
+{
+stack: f{0<-1> :: (0 = (x - 1))<0> :: f(0 = (x - 1))<1>(fun<f>,) :: return f(0 = (x - 1));<0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- handle value 0 with (0 = (x - 1))<1>(0,) --->
+{
+stack: f{(0 = 0@7)<-1> :: f(0 = (x - 1))<1>(fun<f>,) :: return f(0 = (x - 1));<0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 0, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- handle value (0 = 0@7) with f(0 = (x - 1))<2>(fun<f>,(0 = 0@7),) --->
+pattern_match((0 = Int: x@0), (0 = 0@7))
+pattern_match(Int: x, 0)
+{
+stack: f{if ((x == 0))
+ ... 
+else
+ ... <-1>} :: f{return f(0 = (x - 1));<0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 0, 0, 
+env: x: 0, main: fun<main>, f: fun<f>, 
+}
+--- step stmt if ((x == 0))
+ ... 
+else
+ ...  --->
+{
+stack: f{(x == 0)<-1> :: if ((x == 0))
+ ... 
+else
+ ... <0>} :: f{return f(0 = (x - 1));<0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 0, 0, 
+env: x: 0, main: fun<main>, f: fun<f>, 
+}
+--- step exp (x == 0) --->
+{
+stack: f{x<-1> :: (x == 0)<0> :: if ((x == 0))
+ ... 
+else
+ ... <0>} :: f{return f(0 = (x - 1));<0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 0, 0, 
+env: x: 0, main: fun<main>, f: fun<f>, 
+}
+--- step exp x --->
+{
+stack: f{0<-1> :: (x == 0)<0> :: if ((x == 0))
+ ... 
+else
+ ... <0>} :: f{return f(0 = (x - 1));<0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 0, 0, 
+env: x: 0, main: fun<main>, f: fun<f>, 
+}
+--- handle value 0 with (x == 0)<1>(0,) --->
+{
+stack: f{0<-1> :: (x == 0)<1>(0,) :: if ((x == 0))
+ ... 
+else
+ ... <0>} :: f{return f(0 = (x - 1));<0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 0, 0, 
+env: x: 0, main: fun<main>, f: fun<f>, 
+}
+--- step exp 0 --->
+{
+stack: f{0<-1> :: (x == 0)<1>(0,) :: if ((x == 0))
+ ... 
+else
+ ... <0>} :: f{return f(0 = (x - 1));<0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 0, 0, 
+env: x: 0, main: fun<main>, f: fun<f>, 
+}
+--- handle value 0 with (x == 0)<2>(0,0,) --->
+{
+stack: f{true<-1> :: if ((x == 0))
+ ... 
+else
+ ... <0>} :: f{return f(0 = (x - 1));<0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 0, 0, 
+env: x: 0, main: fun<main>, f: fun<f>, 
+}
+--- handle value true with if ((x == 0))
+ ... 
+else
+ ... <1>(true,) --->
+{
+stack: f{return x;<-1>} :: f{return f(0 = (x - 1));<0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 0, 0, 
+env: x: 0, main: fun<main>, f: fun<f>, 
+}
+--- step stmt return x; --->
+{
+stack: f{x<-1> :: return x;<0>} :: f{return f(0 = (x - 1));<0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 0, 0, 
+env: x: 0, main: fun<main>, f: fun<f>, 
+}
+--- step exp x --->
+{
+stack: f{0<-1> :: return x;<0>} :: f{return f(0 = (x - 1));<0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 0, 0, 
+env: x: 0, main: fun<main>, f: fun<f>, 
+}
+--- handle value 0 with return x;<1>(0,) --->
+{
+stack: f{0<-1> :: return f(0 = (x - 1));<0>} :: f{return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, 1, 0, !!0, 
+env: x: 1, main: fun<main>, f: fun<f>, 
+}
+--- handle value 0 with return f(0 = (x - 1));<1>(0,) --->
+{
+stack: f{0<-1> :: return f(0 = (x - 1));<0>} :: main{return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, 2, 1, !!1, 0, !!0, 
+env: x: 2, main: fun<main>, f: fun<f>, 
+}
+--- handle value 0 with return f(0 = (x - 1));<1>(0,) --->
+{
+stack: main{0<-1> :: return f(0 = 2);<0>} :: top{}
+heap: Int: x, fun<f>, fun<main>, 2, !!2, 1, !!1, 0, !!0, 
+env: main: fun<main>, f: fun<f>, 
+}
+--- handle value 0 with return f(0 = 2);<1>(0,) --->
+{
+stack: top{0<-1>}
+heap: Int: x, fun<f>, fun<main>, 2, !!2, 1, !!1, 0, !!0, 
+env: main: fun<main>, f: fun<f>, 
+}
+result: 0
diff --git a/executable_semantics/testdata/funptr1.golden b/executable_semantics/testdata/funptr1.golden
index b4ee8bfcb6bd..c5bf12ded2c2 100644
--- a/executable_semantics/testdata/funptr1.golden
+++ b/executable_semantics/testdata/funptr1.golden
@@ -1,10 +1,10 @@
 ********** source program **********
-fn add1 Int: x -> Int {
+fn add1 (0 = Int: x) -> Int {
 return (x + 1);
 
 }
 fn main () -> Int {
-var fn Int -> Int: f = add1;
+var fn (0 = Int) -> Int: f = add1;
 return f(0 = (- 1));
 
 }
@@ -15,12 +15,260 @@ return f(0 = (- 1));
 --- step exp Int --->
 --- step exp Int --->
 --- step exp Int --->
---- step exp fn Int -> Int --->
+--- step exp fn (0 = Int) -> Int --->
+--- step exp (0 = Int) --->
 --- step exp Int --->
---- handle value Int with fn Int -> Int<1>(Int,) --->
+--- handle value Int with (0 = Int)<1>(Int,) --->
+--- handle value (0 = Int@0) with fn (0 = Int) -> Int<1>((0 = Int@0),) --->
 --- step exp Int --->
---- handle value Int with fn Int -> Int<2>(Int,Int,) --->
-11: type error in call
-expected: Int
-actual: Tuple(0 = Int)
-EXIT CODE: 255
+--- handle value Int with fn (0 = Int) -> Int<2>((0 = Int@0),Int,) --->
+
+********** type checking complete **********
+fn add1 (0 = Int: x) -> Int {
+return (x + 1);
+}
+fn main () -> Int {
+var fn (0 = Int) -> Int: f = add1;
+return f(0 = (- 1));
+}
+********** starting execution **********
+********** initializing globals **********
+--- step exp (0 = Int: x) --->
+--- step exp Int: x --->
+--- step exp Int --->
+--- handle value Int with Int: x<1>(Int,) --->
+--- handle value Int: x with (0 = Int: x)<1>(Int: x,) --->
+--- step exp () --->
+********** calling main function **********
+{
+stack: top{main()<-1>}
+heap: Int: x, fun<add1>, fun<main>, 
+env: main: fun<main>, add1: fun<add1>, 
+}
+--- step exp main() --->
+{
+stack: top{main<-1> :: main()<0>}
+heap: Int: x, fun<add1>, fun<main>, 
+env: main: fun<main>, add1: fun<add1>, 
+}
+--- step exp main --->
+{
+stack: top{fun<main><-1> :: main()<0>}
+heap: Int: x, fun<add1>, fun<main>, 
+env: main: fun<main>, add1: fun<add1>, 
+}
+--- handle value fun<main> with main()<1>(fun<main>,) --->
+{
+stack: top{()<-1> :: main()<1>(fun<main>,)}
+heap: Int: x, fun<add1>, fun<main>, 
+env: main: fun<main>, add1: fun<add1>, 
+}
+--- step exp () --->
+{
+stack: top{()<-1> :: main()<1>(fun<main>,)}
+heap: Int: x, fun<add1>, fun<main>, 
+env: main: fun<main>, add1: fun<add1>, 
+}
+--- handle value () with main()<2>(fun<main>,(),) --->
+pattern_match((), ())
+{
+stack: main{var fn (0 = Int) -> Int: f = add1; ... <-1>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, 
+env: main: fun<main>, add1: fun<add1>, 
+}
+--- step stmt var fn (0 = Int) -> Int: f = add1; ...  --->
+{
+stack: main{var fn (0 = Int) -> Int: f = add1;<-1> :: return f(0 = (- 1));<-1>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, 
+env: main: fun<main>, add1: fun<add1>, 
+}
+--- step stmt var fn (0 = Int) -> Int: f = add1; --->
+{
+stack: main{add1<-1> :: var fn (0 = Int) -> Int: f = add1;<0> :: return f(0 = (- 1));<-1>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, 
+env: main: fun<main>, add1: fun<add1>, 
+}
+--- step exp add1 --->
+{
+stack: main{fun<add1><-1> :: var fn (0 = Int) -> Int: f = add1;<0> :: return f(0 = (- 1));<-1>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, 
+env: main: fun<main>, add1: fun<add1>, 
+}
+--- handle value fun<add1> with var fn (0 = Int) -> Int: f = add1;<1>(fun<add1>,) --->
+{
+stack: main{fn (0 = Int) -> Int: f<-1> :: var fn (0 = Int) -> Int: f = add1;<1>(fun<add1>,) :: return f(0 = (- 1));<-1>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, 
+env: main: fun<main>, add1: fun<add1>, 
+}
+--- step exp fn (0 = Int) -> Int: f --->
+{
+stack: main{fn (0 = Int) -> Int<-1> :: fn (0 = Int) -> Int: f<0> :: var fn (0 = Int) -> Int: f = add1;<1>(fun<add1>,) :: return f(0 = (- 1));<-1>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, 
+env: main: fun<main>, add1: fun<add1>, 
+}
+--- step exp fn (0 = Int) -> Int --->
+{
+stack: main{(0 = Int)<-1> :: fn (0 = Int) -> Int<0> :: fn (0 = Int) -> Int: f<0> :: var fn (0 = Int) -> Int: f = add1;<1>(fun<add1>,) :: return f(0 = (- 1));<-1>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, 
+env: main: fun<main>, add1: fun<add1>, 
+}
+--- step exp (0 = Int) --->
+{
+stack: main{Int<-1> :: (0 = Int)<0> :: fn (0 = Int) -> Int<0> :: fn (0 = Int) -> Int: f<0> :: var fn (0 = Int) -> Int: f = add1;<1>(fun<add1>,) :: return f(0 = (- 1));<-1>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, 
+env: main: fun<main>, add1: fun<add1>, 
+}
+--- step exp Int --->
+{
+stack: main{Int<-1> :: (0 = Int)<0> :: fn (0 = Int) -> Int<0> :: fn (0 = Int) -> Int: f<0> :: var fn (0 = Int) -> Int: f = add1;<1>(fun<add1>,) :: return f(0 = (- 1));<-1>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, 
+env: main: fun<main>, add1: fun<add1>, 
+}
+--- handle value Int with (0 = Int)<1>(Int,) --->
+{
+stack: main{(0 = Int@3)<-1> :: fn (0 = Int) -> Int<0> :: fn (0 = Int) -> Int: f<0> :: var fn (0 = Int) -> Int: f = add1;<1>(fun<add1>,) :: return f(0 = (- 1));<-1>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, Int, 
+env: main: fun<main>, add1: fun<add1>, 
+}
+--- handle value (0 = Int@3) with fn (0 = Int) -> Int<1>((0 = Int@3),) --->
+{
+stack: main{Int<-1> :: fn (0 = Int) -> Int<1>((0 = Int@3),) :: fn (0 = Int) -> Int: f<0> :: var fn (0 = Int) -> Int: f = add1;<1>(fun<add1>,) :: return f(0 = (- 1));<-1>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, Int, 
+env: main: fun<main>, add1: fun<add1>, 
+}
+--- step exp Int --->
+{
+stack: main{Int<-1> :: fn (0 = Int) -> Int<1>((0 = Int@3),) :: fn (0 = Int) -> Int: f<0> :: var fn (0 = Int) -> Int: f = add1;<1>(fun<add1>,) :: return f(0 = (- 1));<-1>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, Int, 
+env: main: fun<main>, add1: fun<add1>, 
+}
+--- handle value Int with fn (0 = Int) -> Int<2>((0 = Int@3),Int,) --->
+{
+stack: main{fn (0 = Int@3) -> Int<-1> :: fn (0 = Int) -> Int: f<0> :: var fn (0 = Int) -> Int: f = add1;<1>(fun<add1>,) :: return f(0 = (- 1));<-1>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, Int, 
+env: main: fun<main>, add1: fun<add1>, 
+}
+--- handle value fn (0 = Int@3) -> Int with fn (0 = Int) -> Int: f<1>(fn (0 = Int@3) -> Int,) --->
+{
+stack: main{fn (0 = Int@3) -> Int: f<-1> :: var fn (0 = Int) -> Int: f = add1;<1>(fun<add1>,) :: return f(0 = (- 1));<-1>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, Int, 
+env: main: fun<main>, add1: fun<add1>, 
+}
+--- handle value fn (0 = Int@3) -> Int: f with var fn (0 = Int) -> Int: f = add1;<2>(fun<add1>,fn (0 = Int@3) -> Int: f,) --->
+pattern_match(fn (0 = Int@3) -> Int: f, fun<add1>)
+{
+stack: main{return f(0 = (- 1));<-1>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, Int, fun<add1>, 
+env: f: fun<add1>, main: fun<main>, add1: fun<add1>, 
+}
+--- step stmt return f(0 = (- 1)); --->
+{
+stack: main{f(0 = (- 1))<-1> :: return f(0 = (- 1));<0>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, Int, fun<add1>, 
+env: f: fun<add1>, main: fun<main>, add1: fun<add1>, 
+}
+--- step exp f(0 = (- 1)) --->
+{
+stack: main{f<-1> :: f(0 = (- 1))<0> :: return f(0 = (- 1));<0>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, Int, fun<add1>, 
+env: f: fun<add1>, main: fun<main>, add1: fun<add1>, 
+}
+--- step exp f --->
+{
+stack: main{fun<add1><-1> :: f(0 = (- 1))<0> :: return f(0 = (- 1));<0>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, Int, fun<add1>, 
+env: f: fun<add1>, main: fun<main>, add1: fun<add1>, 
+}
+--- handle value fun<add1> with f(0 = (- 1))<1>(fun<add1>,) --->
+{
+stack: main{(0 = (- 1))<-1> :: f(0 = (- 1))<1>(fun<add1>,) :: return f(0 = (- 1));<0>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, Int, fun<add1>, 
+env: f: fun<add1>, main: fun<main>, add1: fun<add1>, 
+}
+--- step exp (0 = (- 1)) --->
+{
+stack: main{(- 1)<-1> :: (0 = (- 1))<0> :: f(0 = (- 1))<1>(fun<add1>,) :: return f(0 = (- 1));<0>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, Int, fun<add1>, 
+env: f: fun<add1>, main: fun<main>, add1: fun<add1>, 
+}
+--- step exp (- 1) --->
+{
+stack: main{1<-1> :: (- 1)<0> :: (0 = (- 1))<0> :: f(0 = (- 1))<1>(fun<add1>,) :: return f(0 = (- 1));<0>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, Int, fun<add1>, 
+env: f: fun<add1>, main: fun<main>, add1: fun<add1>, 
+}
+--- step exp 1 --->
+{
+stack: main{1<-1> :: (- 1)<0> :: (0 = (- 1))<0> :: f(0 = (- 1))<1>(fun<add1>,) :: return f(0 = (- 1));<0>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, Int, fun<add1>, 
+env: f: fun<add1>, main: fun<main>, add1: fun<add1>, 
+}
+--- handle value 1 with (- 1)<1>(1,) --->
+{
+stack: main{-1<-1> :: (0 = (- 1))<0> :: f(0 = (- 1))<1>(fun<add1>,) :: return f(0 = (- 1));<0>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, Int, fun<add1>, 
+env: f: fun<add1>, main: fun<main>, add1: fun<add1>, 
+}
+--- handle value -1 with (0 = (- 1))<1>(-1,) --->
+{
+stack: main{(0 = -1@5)<-1> :: f(0 = (- 1))<1>(fun<add1>,) :: return f(0 = (- 1));<0>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, Int, fun<add1>, -1, 
+env: f: fun<add1>, main: fun<main>, add1: fun<add1>, 
+}
+--- handle value (0 = -1@5) with f(0 = (- 1))<2>(fun<add1>,(0 = -1@5),) --->
+pattern_match((0 = Int: x@0), (0 = -1@5))
+pattern_match(Int: x, -1)
+{
+stack: add1{return (x + 1);<-1>} :: main{return f(0 = (- 1));<0>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, Int, fun<add1>, -1, -1, 
+env: x: -1, main: fun<main>, add1: fun<add1>, 
+}
+--- step stmt return (x + 1); --->
+{
+stack: add1{(x + 1)<-1> :: return (x + 1);<0>} :: main{return f(0 = (- 1));<0>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, Int, fun<add1>, -1, -1, 
+env: x: -1, main: fun<main>, add1: fun<add1>, 
+}
+--- step exp (x + 1) --->
+{
+stack: add1{x<-1> :: (x + 1)<0> :: return (x + 1);<0>} :: main{return f(0 = (- 1));<0>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, Int, fun<add1>, -1, -1, 
+env: x: -1, main: fun<main>, add1: fun<add1>, 
+}
+--- step exp x --->
+{
+stack: add1{-1<-1> :: (x + 1)<0> :: return (x + 1);<0>} :: main{return f(0 = (- 1));<0>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, Int, fun<add1>, -1, -1, 
+env: x: -1, main: fun<main>, add1: fun<add1>, 
+}
+--- handle value -1 with (x + 1)<1>(-1,) --->
+{
+stack: add1{1<-1> :: (x + 1)<1>(-1,) :: return (x + 1);<0>} :: main{return f(0 = (- 1));<0>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, Int, fun<add1>, -1, -1, 
+env: x: -1, main: fun<main>, add1: fun<add1>, 
+}
+--- step exp 1 --->
+{
+stack: add1{1<-1> :: (x + 1)<1>(-1,) :: return (x + 1);<0>} :: main{return f(0 = (- 1));<0>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, Int, fun<add1>, -1, -1, 
+env: x: -1, main: fun<main>, add1: fun<add1>, 
+}
+--- handle value 1 with (x + 1)<2>(-1,1,) --->
+{
+stack: add1{0<-1> :: return (x + 1);<0>} :: main{return f(0 = (- 1));<0>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, Int, fun<add1>, -1, -1, 
+env: x: -1, main: fun<main>, add1: fun<add1>, 
+}
+--- handle value 0 with return (x + 1);<1>(0,) --->
+{
+stack: main{0<-1> :: return f(0 = (- 1));<0>} :: top{}
+heap: Int: x, fun<add1>, fun<main>, Int, fun<add1>, -1, !!-1, 
+env: f: fun<add1>, main: fun<main>, add1: fun<add1>, 
+}
+--- handle value 0 with return f(0 = (- 1));<1>(0,) --->
+{
+stack: top{0<-1>}
+heap: Int: x, fun<add1>, fun<main>, Int, !!fun<add1>, -1, !!-1, 
+env: main: fun<main>, add1: fun<add1>, 
+}
+result: 0