diff --git a/explorer/interpreter/BUILD b/explorer/interpreter/BUILD
index b2ec4791c7a2..169b46857433 100644
--- a/explorer/interpreter/BUILD
+++ b/explorer/interpreter/BUILD
@@ -43,6 +43,7 @@ cc_library(
         "//common:error",
         "//common:ostream",
         "//explorer/ast",
+        "//explorer/common:trace_stream",
         "@llvm-project//llvm:Support",
     ],
 )
@@ -87,6 +88,7 @@ cc_library(
         "//explorer/common:error_builders",
         "//explorer/common:nonnull",
         "//explorer/common:source_location",
+        "//explorer/common:trace_stream",
         "@llvm-project//llvm:Support",
     ],
 )
diff --git a/explorer/interpreter/action_stack.cpp b/explorer/interpreter/action_stack.cpp
index f58b77cc8b6f..c6ada2f77929 100644
--- a/explorer/interpreter/action_stack.cpp
+++ b/explorer/interpreter/action_stack.cpp
@@ -22,7 +22,7 @@ void ActionStack::Print(llvm::raw_ostream& out) const {
 void ActionStack::Start(std::unique_ptr<Action> action) {
   result_ = std::nullopt;
   CARBON_CHECK(todo_.empty());
-  todo_.Push(std::move(action));
+  Push(std::move(action));
 }
 
 void ActionStack::Initialize(ValueNodeView value_node,
@@ -129,7 +129,7 @@ static auto FinishActionKindFor(Action::Kind kind) -> FinishActionKind {
 
 auto ActionStack::FinishAction() -> ErrorOr<Success> {
   std::stack<std::unique_ptr<Action>> scopes_to_destroy;
-  std::unique_ptr<Action> act = todo_.Pop();
+  std::unique_ptr<Action> act = Pop();
   switch (FinishActionKindFor(act->kind())) {
     case FinishActionKind::Value:
       CARBON_FATAL() << "This kind of action must produce a result: " << *act;
@@ -147,7 +147,7 @@ auto ActionStack::FinishAction() -> ErrorOr<Success> {
 auto ActionStack::FinishAction(Nonnull<const Value*> result)
     -> ErrorOr<Success> {
   std::stack<std::unique_ptr<Action>> scopes_to_destroy;
-  std::unique_ptr<Action> act = todo_.Pop();
+  std::unique_ptr<Action> act = Pop();
   switch (FinishActionKindFor(act->kind())) {
     case FinishActionKind::NoValue:
       CARBON_FATAL() << "This kind of action cannot produce results: " << *act;
@@ -166,7 +166,7 @@ auto ActionStack::FinishAction(Nonnull<const Value*> result)
 auto ActionStack::Spawn(std::unique_ptr<Action> child) -> ErrorOr<Success> {
   Action& action = *todo_.Top();
   action.set_pos(action.pos() + 1);
-  todo_.Push(std::move(child));
+  Push(std::move(child));
   return Success();
 }
 
@@ -174,18 +174,18 @@ auto ActionStack::Spawn(std::unique_ptr<Action> child, RuntimeScope scope)
     -> ErrorOr<Success> {
   Action& action = *todo_.Top();
   action.set_pos(action.pos() + 1);
-  todo_.Push(std::make_unique<ScopeAction>(std::move(scope)));
-  todo_.Push(std::move(child));
+  Push(std::make_unique<ScopeAction>(std::move(scope)));
+  Push(std::move(child));
   return Success();
 }
 
 auto ActionStack::ReplaceWith(std::unique_ptr<Action> replacement)
     -> ErrorOr<Success> {
-  std::unique_ptr<Action> old = todo_.Pop();
+  std::unique_ptr<Action> old = Pop();
   CARBON_CHECK(FinishActionKindFor(old->kind()) ==
                FinishActionKindFor(replacement->kind()))
       << "Can't replace action " << *old << " with " << *replacement;
-  todo_.Push(std::move(replacement));
+  Push(std::move(replacement));
   return Success();
 }
 
@@ -205,7 +205,7 @@ auto ActionStack::UnwindToWithCaptureScopesToDestroy(
         &statement_action->statement() == ast_node) {
       break;
     }
-    auto item = todo_.Pop();
+    auto item = Pop();
     auto& scope = item->scope();
     if (scope && item->kind() != Action::Kind::CleanUpAction) {
       std::unique_ptr<Action> cleanup_action = std::make_unique<CleanUpAction>(
@@ -237,7 +237,7 @@ auto ActionStack::UnwindPastWithCaptureScopesToDestroy(
     Nonnull<const Statement*> ast_node) -> std::stack<std::unique_ptr<Action>> {
   std::stack<std::unique_ptr<Action>> scopes_to_destroy =
       UnwindToWithCaptureScopesToDestroy(ast_node);
-  auto item = todo_.Pop();
+  auto item = Pop();
   scopes_to_destroy.push(std::move(item));
   PopScopes(scopes_to_destroy);
   return scopes_to_destroy;
@@ -255,7 +255,7 @@ auto ActionStack::UnwindPast(Nonnull<const Statement*> ast_node,
 void ActionStack::PopScopes(
     std::stack<std::unique_ptr<Action>>& cleanup_stack) {
   while (!todo_.empty() && llvm::isa<ScopeAction>(*todo_.Top())) {
-    auto act = todo_.Pop();
+    auto act = Pop();
     if (act->scope()) {
       cleanup_stack.push(std::move(act));
     }
@@ -279,7 +279,7 @@ void ActionStack::PushCleanUpActions(
       std::unique_ptr<Action> cleanup_action = std::make_unique<CleanUpAction>(
           std::move(*act->scope()),
           SourceLocation("stack cleanup", 1, FileKind::Unknown));
-      todo_.Push(std::move(cleanup_action));
+      Push(std::move(cleanup_action));
     }
     actions.pop();
   }
@@ -292,7 +292,7 @@ void ActionStack::PushCleanUpAction(std::unique_ptr<Action> act) {
     std::unique_ptr<Action> cleanup_action = std::make_unique<CleanUpAction>(
         std::move(*scope),
         SourceLocation("stack cleanup", 1, FileKind::Unknown));
-    todo_.Push(std::move(cleanup_action));
+    Push(std::move(cleanup_action));
   }
 }
 
diff --git a/explorer/interpreter/action_stack.h b/explorer/interpreter/action_stack.h
index bb6d7aea8871..7a2c4787f205 100644
--- a/explorer/interpreter/action_stack.h
+++ b/explorer/interpreter/action_stack.h
@@ -12,6 +12,7 @@
 #include "common/ostream.h"
 #include "explorer/ast/statement.h"
 #include "explorer/ast/value.h"
+#include "explorer/common/trace_stream.h"
 #include "explorer/interpreter/action.h"
 
 namespace Carbon {
@@ -23,12 +24,16 @@ enum class Phase { CompileTime, RunTime };
 class ActionStack {
  public:
   // Constructs an empty compile-time ActionStack.
-  ActionStack() : phase_(Phase::CompileTime) {}
+  explicit ActionStack(Nonnull<TraceStream*> trace_stream)
+      : phase_(Phase::CompileTime), trace_stream_(trace_stream) {}
 
   // Constructs an empty run-time ActionStack that allocates global variables
   // on `heap`.
-  explicit ActionStack(Nonnull<HeapAllocationInterface*> heap)
-      : globals_(RuntimeScope(heap)), phase_(Phase::RunTime) {}
+  explicit ActionStack(Nonnull<TraceStream*> trace_stream,
+                       Nonnull<HeapAllocationInterface*> heap)
+      : globals_(RuntimeScope(heap)),
+        phase_(Phase::RunTime),
+        trace_stream_(trace_stream) {}
 
   void Print(llvm::raw_ostream& out) const;
   LLVM_DUMP_METHOD void Dump() const { Print(llvm::errs()); }
@@ -104,7 +109,20 @@ class ActionStack {
   auto UnwindPast(Nonnull<const Statement*> ast_node,
                   Nonnull<const Value*> result) -> ErrorOr<Success>;
 
-  void Pop() { todo_.Pop(); }
+  auto Pop() -> std::unique_ptr<Action> {
+    auto popped_action = todo_.Pop();
+    if (trace_stream_->is_enabled()) {
+      *trace_stream_ << "(-) stack-pop: " << *popped_action << "\n";
+    }
+    return popped_action;
+  }
+
+  void Push(std::unique_ptr<Action> action) {
+    if (trace_stream_->is_enabled()) {
+      *trace_stream_ << "(+) stack-push: " << *action << "\n";
+    }
+    todo_.Push(std::move(action));
+  }
 
   auto size() const -> int { return todo_.size(); }
 
@@ -136,6 +154,7 @@ class ActionStack {
   std::optional<Nonnull<const Value*>> result_;
   std::optional<RuntimeScope> globals_;
   Phase phase_;
+  Nonnull<TraceStream*> trace_stream_;
 };
 
 }  // namespace Carbon
diff --git a/explorer/interpreter/heap.cpp b/explorer/interpreter/heap.cpp
index 4abcdf191104..c9279e534d03 100644
--- a/explorer/interpreter/heap.cpp
+++ b/explorer/interpreter/heap.cpp
@@ -21,12 +21,21 @@ auto Heap::AllocateValue(Nonnull<const Value*> v) -> AllocationId {
   // to leave it up to the caller.
   AllocationId a(values_.size());
   values_.push_back(v);
+  bool is_uninitialized = false;
+
   if (v->kind() == Carbon::Value::Kind::UninitializedValue) {
     states_.push_back(ValueState::Uninitialized);
+    is_uninitialized = true;
   } else {
     states_.push_back(ValueState::Alive);
   }
   bound_values_.push_back(llvm::DenseMap<const AstNode*, Address>{});
+
+  if (trace_stream_->is_enabled()) {
+    *trace_stream_ << "(+) memory-alloc: #" << a.index_ << " `" << *v << "`"
+                   << (is_uninitialized ? " uninitialized" : "") << "\n";
+  }
+
   return a;
 }
 
@@ -35,7 +44,15 @@ auto Heap::Read(const Address& a, SourceLocation source_loc) const
   CARBON_RETURN_IF_ERROR(this->CheckInit(a.allocation_, source_loc));
   CARBON_RETURN_IF_ERROR(this->CheckAlive(a.allocation_, source_loc));
   Nonnull<const Value*> value = values_[a.allocation_.index_];
-  return value->GetElement(arena_, a.element_path_, source_loc, value);
+  ErrorOr<Nonnull<const Value*>> read_value =
+      value->GetElement(arena_, a.element_path_, source_loc, value);
+
+  if (trace_stream_->is_enabled()) {
+    *trace_stream_ << "+++ memory-read: #" << a.allocation_.index_ << " `"
+                   << **read_value << "`\n";
+  }
+
+  return read_value;
 }
 
 auto Heap::Write(const Address& a, Nonnull<const Value*> v,
@@ -64,6 +81,12 @@ auto Heap::Write(const Address& a, Nonnull<const Value*> v,
       }
     }
   }
+
+  if (trace_stream_->is_enabled()) {
+    *trace_stream_ << "+++ memory-write: #" << a.allocation_.index_ << " `"
+                   << *values_[a.allocation_.index_] << "`\n";
+  }
+
   return Success();
 }
 
@@ -95,6 +118,12 @@ auto Heap::Deallocate(AllocationId allocation) -> ErrorOr<Success> {
     CARBON_FATAL() << "deallocating an already dead value: "
                    << *values_[allocation.index_];
   }
+
+  if (trace_stream_->is_enabled()) {
+    *trace_stream_ << "(-) memory-dealloc: #" << allocation.index_ << " `"
+                   << *values_[allocation.index_] << "`\n";
+  }
+
   return Success();
 }
 
diff --git a/explorer/interpreter/heap.h b/explorer/interpreter/heap.h
index 20b975db60dd..d701639c1053 100644
--- a/explorer/interpreter/heap.h
+++ b/explorer/interpreter/heap.h
@@ -13,6 +13,7 @@
 #include "explorer/ast/value_node.h"
 #include "explorer/common/nonnull.h"
 #include "explorer/common/source_location.h"
+#include "explorer/common/trace_stream.h"
 #include "explorer/interpreter/heap_allocation_interface.h"
 
 namespace Carbon {
@@ -28,7 +29,8 @@ class Heap : public HeapAllocationInterface {
   };
 
   // Constructs an empty Heap.
-  explicit Heap(Nonnull<Arena*> arena) : arena_(arena){};
+  explicit Heap(Nonnull<TraceStream*> trace_stream, Nonnull<Arena*> arena)
+      : arena_(arena), trace_stream_(trace_stream){};
 
   Heap(const Heap&) = delete;
   auto operator=(const Heap&) -> Heap& = delete;
@@ -96,6 +98,7 @@ class Heap : public HeapAllocationInterface {
   std::vector<Nonnull<const Value*>> values_;
   std::vector<ValueState> states_;
   std::vector<llvm::DenseMap<const AstNode*, Address>> bound_values_;
+  Nonnull<TraceStream*> trace_stream_;
 };
 
 }  // namespace Carbon
diff --git a/explorer/interpreter/interpreter.cpp b/explorer/interpreter/interpreter.cpp
index f3c9dd500914..dc8a14271471 100644
--- a/explorer/interpreter/interpreter.cpp
+++ b/explorer/interpreter/interpreter.cpp
@@ -48,12 +48,13 @@ static constexpr int64_t MaxStepsTaken = 1e6;
 static constexpr int64_t MaxArenaAllocated = 1e9;
 
 // Constructs an ActionStack suitable for the specified phase.
-static auto MakeTodo(Phase phase, Nonnull<Heap*> heap) -> ActionStack {
+static auto MakeTodo(Phase phase, Nonnull<Heap*> heap,
+                     Nonnull<TraceStream*> trace_stream) -> ActionStack {
   switch (phase) {
     case Phase::CompileTime:
-      return ActionStack();
+      return ActionStack(trace_stream);
     case Phase::RunTime:
-      return ActionStack(heap);
+      return ActionStack(trace_stream, heap);
   }
 }
 
@@ -69,8 +70,8 @@ class Interpreter {
               Nonnull<TraceStream*> trace_stream,
               Nonnull<llvm::raw_ostream*> print_stream)
       : arena_(arena),
-        heap_(arena),
-        todo_(MakeTodo(phase, &heap_)),
+        heap_(trace_stream, arena),
+        todo_(MakeTodo(phase, &heap_, trace_stream)),
         trace_stream_(trace_stream),
         print_stream_(print_stream),
         phase_(phase) {}
@@ -181,8 +182,6 @@ class Interpreter {
   auto CallDestructor(Nonnull<const DestructorDeclaration*> fun,
                       Nonnull<const Value*> receiver) -> ErrorOr<Success>;
 
-  void TraceState();
-
   auto phase() const -> Phase { return phase_; }
 
   Nonnull<Arena*> arena_;
@@ -206,10 +205,6 @@ class Interpreter {
 // State Operations
 //
 
-void Interpreter::TraceState() {
-  *trace_stream_ << "{\nstack: " << todo_ << "\nmemory: " << heap_ << "\n}\n";
-}
-
 auto Interpreter::EvalPrim(Operator op, Nonnull<const Value*> /*static_type*/,
                            const std::vector<Nonnull<const Value*>>& args,
                            SourceLocation source_loc)
@@ -651,10 +646,6 @@ auto Interpreter::StepLocation() -> ErrorOr<Success> {
 
 auto Interpreter::EvalRecursively(std::unique_ptr<Action> action)
     -> ErrorOr<Nonnull<const Value*>> {
-  if (trace_stream_->is_enabled()) {
-    TraceState();
-  }
-
   todo_.BeginRecursiveAction();
   CARBON_RETURN_IF_ERROR(todo_.Spawn(std::move(action)));
   // Note that the only `RecursiveAction` we can encounter here is our own --
@@ -662,9 +653,6 @@ auto Interpreter::EvalRecursively(std::unique_ptr<Action> action)
   // action is finished and popped off the queue before returning to us.
   while (!isa<RecursiveAction>(todo_.CurrentAction())) {
     CARBON_RETURN_IF_ERROR(Step());
-    if (trace_stream_->is_enabled()) {
-      TraceState();
-    }
   }
   if (trace_stream_->is_enabled()) {
     *trace_stream_ << "--- recursive eval done\n";
@@ -2766,15 +2754,9 @@ auto Interpreter::Step() -> ErrorOr<Success> {
 
 auto Interpreter::RunAllSteps(std::unique_ptr<Action> action)
     -> ErrorOr<Success> {
-  if (trace_stream_->is_enabled()) {
-    TraceState();
-  }
   todo_.Start(std::move(action));
   while (!todo_.empty()) {
     CARBON_RETURN_IF_ERROR(Step());
-    if (trace_stream_->is_enabled()) {
-      TraceState();
-    }
   }
   return Success();
 }
diff --git a/explorer/trace_testdata/full_trace.carbon b/explorer/trace_testdata/full_trace.carbon
index 7ac1f24a0a79..33abc8133453 100644
--- a/explorer/trace_testdata/full_trace.carbon
+++ b/explorer/trace_testdata/full_trace.carbon
@@ -14,13 +14,13 @@
 // CHECK:STDOUT: }
 // CHECK:STDOUT: fn Main ()-> i32 {
 // CHECK:STDOUT: {
-// CHECK:STDOUT: return N.Foo(0);
+// CHECK:STDOUT: var x: i32 = N.Foo(0);
+// CHECK:STDOUT: return x;
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: }
 // CHECK:STDOUT: ********** resolving names **********
 
-
 package ExplorerTest api;
 
 // CHECK:STDOUT: --- declared `TestInterface` as `interface TestInterface` in `package` (full_trace.carbon:[[@LINE+1]])
@@ -36,37 +36,42 @@ fn N.Foo(n: i32) -> i32 {
 }
 
 fn Main() -> i32 {
-  return N.Foo(0);
-// CHECK:STDOUT: --- declared `Main` as `fn Main` in `package` (full_trace.carbon:[[@LINE+440]])
-// CHECK:STDOUT: ** resolving decl `interface TestInterface` (full_trace.carbon:[[@LINE-14]])
+  var x: i32 = N.Foo(0);
+  return x;
+// CHECK:STDOUT: --- declared `Main` as `fn Main` in `package` (full_trace.carbon:[[@LINE+310]])
+// CHECK:STDOUT: ** resolving decl `interface TestInterface` (full_trace.carbon:[[@LINE-15]])
 // CHECK:STDOUT: --- marked `TestInterface` declared but not usable in `package`
 // CHECK:STDOUT: --- marked `TestInterface` usable in `package`
-// CHECK:STDOUT: --- declared `Self` as `Self` in `interface TestInterface` (full_trace.carbon:[[@LINE-17]])
-// CHECK:STDOUT: ** finished resolving decl `interface TestInterface` (full_trace.carbon:[[@LINE-18]])
-// CHECK:STDOUT: ** resolving decl `namespace N` (full_trace.carbon:[[@LINE-16]])
+// CHECK:STDOUT: --- declared `Self` as `Self` in `interface TestInterface` (full_trace.carbon:[[@LINE-18]])
+// CHECK:STDOUT: ** finished resolving decl `interface TestInterface` (full_trace.carbon:[[@LINE-19]])
+// CHECK:STDOUT: ** resolving decl `namespace N` (full_trace.carbon:[[@LINE-17]])
 // CHECK:STDOUT: --- marked `N` usable in `package`
-// CHECK:STDOUT: ** finished resolving decl `namespace N` (full_trace.carbon:[[@LINE-18]])
-// CHECK:STDOUT: ** resolving decl `fn N.Foo` (full_trace.carbon:[[@LINE-13]])
-// CHECK:STDOUT: --- resolved `N` as `namespace N` in `package` (full_trace.carbon:[[@LINE-17]])
+// CHECK:STDOUT: ** finished resolving decl `namespace N` (full_trace.carbon:[[@LINE-19]])
+// CHECK:STDOUT: ** resolving decl `fn N.Foo` (full_trace.carbon:[[@LINE-14]])
+// CHECK:STDOUT: --- resolved `N` as `namespace N` in `package` (full_trace.carbon:[[@LINE-18]])
 // CHECK:STDOUT: --- marked `Foo` declared but not usable in `namespace N`
-// CHECK:STDOUT: --- declared `n` as `n` in `fn N.Foo` (full_trace.carbon:[[@LINE-19]])
+// CHECK:STDOUT: --- declared `n` as `n` in `fn N.Foo` (full_trace.carbon:[[@LINE-20]])
 // CHECK:STDOUT: --- marked `Foo` usable in `namespace N`
-// CHECK:STDOUT: ** resolving stmt `{return (n + 1);}` (full_trace.carbon:[[@LINE-18]])
-// CHECK:STDOUT: ** resolving stmt `return (n + 1);` (full_trace.carbon:[[@LINE-21]])
-// CHECK:STDOUT: --- resolved `n` as `n` in `fn N.Foo` (full_trace.carbon:[[@LINE-22]])
-// CHECK:STDOUT: ** finished resolving stmt `return (n + 1);` (full_trace.carbon:[[@LINE-23]])
-// CHECK:STDOUT: ** finished resolving stmt `{return (n + 1);}` (full_trace.carbon:[[@LINE-22]])
-// CHECK:STDOUT: ** finished resolving decl `fn N.Foo` (full_trace.carbon:[[@LINE-23]])
-// CHECK:STDOUT: ** resolving decl `fn Main` (full_trace.carbon:[[@LINE+420]])
+// CHECK:STDOUT: ** resolving stmt `{return (n + 1);}` (full_trace.carbon:[[@LINE-19]])
+// CHECK:STDOUT: ** resolving stmt `return (n + 1);` (full_trace.carbon:[[@LINE-22]])
+// CHECK:STDOUT: --- resolved `n` as `n` in `fn N.Foo` (full_trace.carbon:[[@LINE-23]])
+// CHECK:STDOUT: ** finished resolving stmt `return (n + 1);` (full_trace.carbon:[[@LINE-24]])
+// CHECK:STDOUT: ** finished resolving stmt `{return (n + 1);}` (full_trace.carbon:[[@LINE-23]])
+// CHECK:STDOUT: ** finished resolving decl `fn N.Foo` (full_trace.carbon:[[@LINE-24]])
+// CHECK:STDOUT: ** resolving decl `fn Main` (full_trace.carbon:[[@LINE+290]])
 // CHECK:STDOUT: --- marked `Main` declared but not usable in `package`
 // CHECK:STDOUT: --- marked `Main` usable in `package`
-// CHECK:STDOUT: ** resolving stmt `{return N.Foo(0);}` (full_trace.carbon:[[@LINE+417]])
-// CHECK:STDOUT: ** resolving stmt `return N.Foo(0);` (full_trace.carbon:[[@LINE-25]])
-// CHECK:STDOUT: --- resolved `N` as `namespace N` in `package` (full_trace.carbon:[[@LINE-26]])
-// CHECK:STDOUT: --- resolved `Foo` as `fn N.Foo` in `namespace N` (full_trace.carbon:[[@LINE-27]])
-// CHECK:STDOUT: ** finished resolving stmt `return N.Foo(0);` (full_trace.carbon:[[@LINE-28]])
-// CHECK:STDOUT: ** finished resolving stmt `{return N.Foo(0);}` (full_trace.carbon:[[@LINE+412]])
-// CHECK:STDOUT: ** finished resolving decl `fn Main` (full_trace.carbon:[[@LINE+411]])
+// CHECK:STDOUT: ** resolving stmt `{var x: i32 = N.Foo(0);return x;}` (full_trace.carbon:[[@LINE+287]])
+// CHECK:STDOUT: ** resolving stmt `var x: i32 = N.Foo(0);` (full_trace.carbon:[[@LINE-26]])
+// CHECK:STDOUT: --- resolved `N` as `namespace N` in `package` (full_trace.carbon:[[@LINE-27]])
+// CHECK:STDOUT: --- resolved `Foo` as `fn N.Foo` in `namespace N` (full_trace.carbon:[[@LINE-28]])
+// CHECK:STDOUT: --- declared `x` as `x` in `{var x: i32 = N.Foo(0);return x;}` (full_trace.carbon:[[@LINE-29]])
+// CHECK:STDOUT: ** finished resolving stmt `var x: i32 = N.Foo(0);` (full_trace.carbon:[[@LINE-30]])
+// CHECK:STDOUT: ** resolving stmt `return x;` (full_trace.carbon:[[@LINE-30]])
+// CHECK:STDOUT: --- resolved `x` as `x` in `{var x: i32 = N.Foo(0);return x;}` (full_trace.carbon:[[@LINE-31]])
+// CHECK:STDOUT: ** finished resolving stmt `return x;` (full_trace.carbon:[[@LINE-32]])
+// CHECK:STDOUT: ** finished resolving stmt `{var x: i32 = N.Foo(0);return x;}` (full_trace.carbon:[[@LINE+278]])
+// CHECK:STDOUT: ** finished resolving decl `fn Main` (full_trace.carbon:[[@LINE+277]])
 // CHECK:STDOUT: --- resolved `Main` as `fn Main` in `package` (<Main()>:0)
 // CHECK:STDOUT: ********** resolving control flow **********
 // CHECK:STDOUT: ********** type checking **********
@@ -83,42 +88,18 @@ fn Main() -> i32 {
 // CHECK:STDOUT: checking BindingPattern n: i32
 // CHECK:STDOUT: checking ExpressionPattern i32
 // CHECK:STDOUT: checking IntTypeLiteral i32
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack:{{ }}
-// CHECK:STDOUT: memory:{{ }}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: i32 .0. ## i32 .1.
-// CHECK:STDOUT: memory:{{ }}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step exp i32 .0. (full_trace.carbon:[[@LINE-61]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: i32 .1. {{[[][[]}}i32]]
-// CHECK:STDOUT: memory:{{ }}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack:{{ }}
-// CHECK:STDOUT: memory:{{ }}
-// CHECK:STDOUT: }
+// CHECK:STDOUT: (+) stack-push: i32 .0.
+// CHECK:STDOUT: (+) stack-push: i32 .0.
+// CHECK:STDOUT: --- step exp i32 .0. (full_trace.carbon:[[@LINE-60]]) --->
+// CHECK:STDOUT: (-) stack-pop: i32 .0.
+// CHECK:STDOUT: (-) stack-pop: i32 .1. {{[[][[]}}i32]]
 // CHECK:STDOUT: finished checking tuple pattern field n: i32
 // CHECK:STDOUT: checking IntTypeLiteral i32
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack:{{ }}
-// CHECK:STDOUT: memory:{{ }}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: i32 .0. ## i32 .1.
-// CHECK:STDOUT: memory:{{ }}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step exp i32 .0. (full_trace.carbon:[[@LINE-80]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: i32 .1. {{[[][[]}}i32]]
-// CHECK:STDOUT: memory:{{ }}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack:{{ }}
-// CHECK:STDOUT: memory:{{ }}
-// CHECK:STDOUT: }
+// CHECK:STDOUT: (+) stack-push: i32 .0.
+// CHECK:STDOUT: (+) stack-push: i32 .0.
+// CHECK:STDOUT: --- step exp i32 .0. (full_trace.carbon:[[@LINE-67]]) --->
+// CHECK:STDOUT: (-) stack-pop: i32 .0.
+// CHECK:STDOUT: (-) stack-pop: i32 .1. {{[[][[]}}i32]]
 // CHECK:STDOUT: ** finished declaring function Foo of type fn (i32,) -> i32
 // CHECK:STDOUT: checking FunctionDeclaration
 // CHECK:STDOUT: ** checking function Foo
@@ -136,33 +117,22 @@ fn Main() -> i32 {
 // CHECK:STDOUT: ** declaring function Main
 // CHECK:STDOUT: checking TuplePattern ()
 // CHECK:STDOUT: checking IntTypeLiteral i32
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack:{{ }}
-// CHECK:STDOUT: memory:{{ }}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: i32 .0. ## i32 .1.
-// CHECK:STDOUT: memory:{{ }}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step exp i32 .0. (full_trace.carbon:[[@LINE-109]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: i32 .1. {{[[][[]}}i32]]
-// CHECK:STDOUT: memory:{{ }}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack:{{ }}
-// CHECK:STDOUT: memory:{{ }}
-// CHECK:STDOUT: }
+// CHECK:STDOUT: (+) stack-push: i32 .0.
+// CHECK:STDOUT: (+) stack-push: i32 .0.
+// CHECK:STDOUT: --- step exp i32 .0. (full_trace.carbon:[[@LINE-84]]) --->
+// CHECK:STDOUT: (-) stack-pop: i32 .0.
+// CHECK:STDOUT: (-) stack-pop: i32 .1. {{[[][[]}}i32]]
 // CHECK:STDOUT: ** finished declaring function Main of type fn () -> i32
 // CHECK:STDOUT: checking FunctionDeclaration
 // CHECK:STDOUT: ** checking function Main
 // CHECK:STDOUT: impl declarations:{{ }}
 // CHECK:STDOUT: impl declarations: bool as interface EqWith(U = bool), i32 as interface EqWith(U = i32), String as interface EqWith(U = String), i32 as interface CompareWith(U = i32), String as interface CompareWith(U = String), i32 as interface LessWith(U = i32), String as interface LessWith(U = String), i32 as interface LessEqWith(U = i32), String as interface LessEqWith(U = String), i32 as interface GreaterWith(U = i32), String as interface GreaterWith(U = String), i32 as interface GreaterEqWith(U = i32), String as interface GreaterEqWith(U = String), i32 as interface Negate, i32 as interface AddWith(U = i32), i32 as interface SubWith(U = i32), i32 as interface MulWith(U = i32), i32 as interface DivWith(U = i32), i32 as interface ModWith(U = i32), i32 as interface BitComplement, i32 as interface BitAndWith(U = i32), i32 as interface BitOrWith(U = i32), i32 as interface BitXorWith(U = i32), i32 as interface LeftShiftWith(U = i32), i32 as interface RightShiftWith(U = i32), i32 as interface Inc, i32 as interface Dec, U as interface __EqualConverter [0], (T1,) as interface As(T = (U1,)) [0, 0, 0; 1, 1, 0, 0, 0], (T1, T2) as interface As(T = (U1, U2)) [0, 0, 0; 0, 0, 1; 1, 1, 0, 0, 0; 1, 1, 0, 0, 1], (T1, U1) as interface EqWith(U = (T2, U2)) [0, 0, 0; 0, 0, 1; 1, 1, 0, 0, 0; 1, 1, 0, 0, 1], (T1, T2, T3) as interface As(T = (U1, U2, U3)) [0, 0, 0; 0, 0, 1; 0, 0, 2; 1, 1, 0, 0, 0; 1, 1, 0, 0, 1; 1, 1, 0, 0, 2], T as interface ImplicitAs(T = U) [0; 1, 1, 0], T as interface As(T = U) [0; 1, 1, 0], T as interface ImplicitAs(T = U) [0; 1, 1, 0], T as interface As(T = U) [0; 1, 1, 0], T as interface AssignWith(U = U) [0; 1, 1, 0], T as interface AddAssignWith(U = U) [0; 1, 1, 0], T as interface SubAssignWith(U = U) [0; 1, 1, 0], T as interface MulAssignWith(U = U) [0; 1, 1, 0], T as interface DivAssignWith(U = U) [0; 1, 1, 0], T as interface ModAssignWith(U = U) [0; 1, 1, 0], T as interface BitAndAssignWith(U = U) [0; 1, 1, 0], T as interface BitOrAssignWith(U = U) [0; 1, 1, 0], T as interface BitXorAssignWith(U = U) [0; 1, 1, 0], T as interface LeftShiftAssignWith(U = U) [0; 1, 1, 0], T as interface RightShiftAssignWith(U = U) [0; 1, 1, 0]
 // CHECK:STDOUT: checking Block {
-// CHECK:STDOUT: return N.Foo(0);
+// CHECK:STDOUT: var x: i32 = N.Foo(0);
+// CHECK:STDOUT: return x;
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: checking ReturnExpression return N.Foo(0);
+// CHECK:STDOUT: checking VariableDefinition var x: i32 = N.Foo(0);
 // CHECK:STDOUT: checking CallExpression N.Foo(0)
 // CHECK:STDOUT: checking SimpleMemberAccessExpression N.Foo
 // CHECK:STDOUT: checking IdentifierExpression Foo
@@ -173,6 +143,16 @@ fn Main() -> i32 {
 // CHECK:STDOUT: performing argument deduction for bindings:{{ }}
 // CHECK:STDOUT: deducing i32 from i32
 // CHECK:STDOUT: deduction succeeded with results: {}
+// CHECK:STDOUT: checking BindingPattern x: i32, expecting i32
+// CHECK:STDOUT: checking ExpressionPattern i32, expecting i32
+// CHECK:STDOUT: checking IntTypeLiteral i32
+// CHECK:STDOUT: (+) stack-push: i32 .0.
+// CHECK:STDOUT: (+) stack-push: i32 .0.
+// CHECK:STDOUT: --- step exp i32 .0. (full_trace.carbon:[[@LINE-112]]) --->
+// CHECK:STDOUT: (-) stack-pop: i32 .0.
+// CHECK:STDOUT: (-) stack-pop: i32 .1. {{[[][[]}}i32]]
+// CHECK:STDOUT: checking ReturnExpression return x;
+// CHECK:STDOUT: checking IdentifierExpression x
 // CHECK:STDOUT: ** finished checking function Main
 // CHECK:STDOUT: checking CallExpression Main()
 // CHECK:STDOUT: checking IdentifierExpression Main
@@ -193,283 +173,174 @@ fn Main() -> i32 {
 // CHECK:STDOUT: }
 // CHECK:STDOUT: fn Main ()-> i32 {
 // CHECK:STDOUT: {
-// CHECK:STDOUT: return N.Foo(0);
+// CHECK:STDOUT: var x: i32 = N.Foo(0);
+// CHECK:STDOUT: return x;
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: }
 // CHECK:STDOUT: ********** starting execution **********
 // CHECK:STDOUT: ********** initializing globals **********
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack:{{ }}
-// CHECK:STDOUT: memory: 0: Heap{}
+// CHECK:STDOUT: (+) stack-push: interface TestInterface {
 // CHECK:STDOUT: }
-// CHECK:STDOUT: --- step decl interface TestInterface .0. (full_trace.carbon:[[@LINE-179]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack:{{ }}
-// CHECK:STDOUT: memory: 0: Heap{}
+// CHECK:STDOUT:  .0.
+// CHECK:STDOUT: --- step decl interface TestInterface .0. (full_trace.carbon:[[@LINE-159]]) --->
+// CHECK:STDOUT: (-) stack-pop: interface TestInterface {
 // CHECK:STDOUT: }
+// CHECK:STDOUT:  .0.
+// CHECK:STDOUT: (+) stack-push: namespace N; .0.
+// CHECK:STDOUT: --- step decl namespace N .0. (full_trace.carbon:[[@LINE-161]]) --->
+// CHECK:STDOUT: (-) stack-pop: namespace N; .0.
+// CHECK:STDOUT: (+) stack-push: fn Foo (n: i32)-> i32 {
 // CHECK:STDOUT: {
-// CHECK:STDOUT: stack:{{ }}
-// CHECK:STDOUT: memory: 0: Heap{}
+// CHECK:STDOUT: return (n + 1);
 // CHECK:STDOUT: }
-// CHECK:STDOUT: --- step decl namespace N .0. (full_trace.carbon:[[@LINE-185]]) --->
+// CHECK:STDOUT:
+// CHECK:STDOUT: }
+// CHECK:STDOUT:  .0.
+// CHECK:STDOUT: --- step decl fn N.Foo .0. (full_trace.carbon:[[@LINE-164]]) --->
+// CHECK:STDOUT: (-) stack-pop: fn Foo (n: i32)-> i32 {
 // CHECK:STDOUT: {
-// CHECK:STDOUT: stack:{{ }}
-// CHECK:STDOUT: memory: 0: Heap{}
+// CHECK:STDOUT: return (n + 1);
 // CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: }
+// CHECK:STDOUT:  .0.
+// CHECK:STDOUT: (+) stack-push: fn Main ()-> i32 {
 // CHECK:STDOUT: {
-// CHECK:STDOUT: stack:{{ }}
-// CHECK:STDOUT: memory: 0: Heap{}
+// CHECK:STDOUT: var x: i32 = N.Foo(0);
+// CHECK:STDOUT: return x;
 // CHECK:STDOUT: }
-// CHECK:STDOUT: --- step decl fn N.Foo .0. (full_trace.carbon:[[@LINE-188]]) --->
+// CHECK:STDOUT:
+// CHECK:STDOUT: }
+// CHECK:STDOUT:  .0.
+// CHECK:STDOUT: --- step decl fn Main .0. (full_trace.carbon:[[@LINE+135]]) --->
+// CHECK:STDOUT: (-) stack-pop: fn Main ()-> i32 {
 // CHECK:STDOUT: {
-// CHECK:STDOUT: stack:{{ }}
-// CHECK:STDOUT: memory: 0: Heap{}
+// CHECK:STDOUT: var x: i32 = N.Foo(0);
+// CHECK:STDOUT: return x;
 // CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack:{{ }}
-// CHECK:STDOUT: memory: 0: Heap{}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step decl fn Main .0. (full_trace.carbon:[[@LINE+247]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack:{{ }}
-// CHECK:STDOUT: memory: 0: Heap{}
+// CHECK:STDOUT:
 // CHECK:STDOUT: }
+// CHECK:STDOUT:  .0.
 // CHECK:STDOUT: ********** calling main function **********
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack:{{ }}
-// CHECK:STDOUT: memory: 0: Heap{}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: Main() .0. ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}
-// CHECK:STDOUT: }
+// CHECK:STDOUT: (+) stack-push: Main() .0.
+// CHECK:STDOUT: (+) stack-push: Main() .0.
 // CHECK:STDOUT: --- step exp Main() .0. (<Main()>:0) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: Main .0. ## Main() .1. ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: Main .0. ## Main .1. ## Main() .1. ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}
-// CHECK:STDOUT: }
+// CHECK:STDOUT: (+) stack-push: Main .0.
+// CHECK:STDOUT: (+) stack-push: Main .0.
 // CHECK:STDOUT: --- step exp Main .0. (<Main()>:0) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: Main .1. {{[[][[]}}fun<Main>]] ## Main() .1. ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: Main() .1. {{[[][[]}}fun<Main>]] ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}
-// CHECK:STDOUT: }
+// CHECK:STDOUT: (-) stack-pop: Main .0.
+// CHECK:STDOUT: (-) stack-pop: Main .1. {{[[][[]}}fun<Main>]]
 // CHECK:STDOUT: --- step exp Main() .1. (<Main()>:0) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: () .0. ## Main() .2. {{[[][[]}}fun<Main>]] ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}
-// CHECK:STDOUT: }
+// CHECK:STDOUT: (+) stack-push: () .0.
 // CHECK:STDOUT: --- step exp () .0. (<Main()>:0) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: Main() .2. {{[[][[]}}fun<Main>, ()]] ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}
-// CHECK:STDOUT: }
+// CHECK:STDOUT: (-) stack-pop: () .0.
 // CHECK:STDOUT: --- step exp Main() .2. (<Main()>:0) --->
 // CHECK:STDOUT: calling function: fun<Main>
 // CHECK:STDOUT: match pattern ()
 // CHECK:STDOUT: from value expression with value ()
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: {return N.Foo(0);} .0. ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step stmt {return N.Foo(0);} .0. (full_trace.carbon:[[@LINE+197]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: return N.Foo(0); .0. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step stmt return N.Foo(0); .0. (full_trace.carbon:[[@LINE-249]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: N.Foo(0) .0. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: N.Foo(0) .0. ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step exp N.Foo(0) .0. (full_trace.carbon:[[@LINE-258]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: N.Foo .0. ## N.Foo(0) .1. ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: N.Foo .0. ## N.Foo .1. ## N.Foo(0) .1. ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step exp N.Foo .0. (full_trace.carbon:[[@LINE-267]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: Foo .0. ## N.Foo .1. ## N.Foo(0) .1. ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step exp Foo .0. (full_trace.carbon:[[@LINE-272]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: N.Foo .1. {{[[][[]}}fun<N.Foo>]] ## N.Foo(0) .1. ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: N.Foo(0) .1. {{[[][[]}}fun<N.Foo>]] ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step exp N.Foo(0) .1. (full_trace.carbon:[[@LINE-281]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: (0) .0. ## N.Foo(0) .2. {{[[][[]}}fun<N.Foo>]] ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step exp (0) .0. (full_trace.carbon:[[@LINE-286]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: 0 .0. ## (0) .1. ## N.Foo(0) .2. {{[[][[]}}fun<N.Foo>]] ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step exp 0 .0. (full_trace.carbon:[[@LINE-291]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: (0) .1. {{[[][[]}}0]] ## N.Foo(0) .2. {{[[][[]}}fun<N.Foo>]] ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step exp (0) .1. (full_trace.carbon:[[@LINE-296]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: N.Foo(0) .2. {{[[][[]}}fun<N.Foo>, (0,)]] ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step exp N.Foo(0) .2. (full_trace.carbon:[[@LINE-301]]) --->
+// CHECK:STDOUT: (+) stack-push: .0. {}
+// CHECK:STDOUT: (+) stack-push: {var x: i32 = N.Foo(0);return x;} .0.
+// CHECK:STDOUT: --- step stmt {var x: i32 = N.Foo(0);return x;} .0. (full_trace.carbon:[[@LINE+107]]) --->
+// CHECK:STDOUT: (+) stack-push: var x: i32 = N.Foo(0); .0.
+// CHECK:STDOUT: --- step stmt var x: i32 = N.Foo(0); .0. (full_trace.carbon:[[@LINE-207]]) --->
+// CHECK:STDOUT: (+) memory-alloc: #1 `Uninit<i32>` uninitialized
+// CHECK:STDOUT: (+) stack-push: N.Foo(0) .0.
+// CHECK:STDOUT: --- step exp N.Foo(0) .0. (full_trace.carbon:[[@LINE-210]]) --->
+// CHECK:STDOUT: (+) stack-push: N.Foo .0.
+// CHECK:STDOUT: (+) stack-push: N.Foo .0.
+// CHECK:STDOUT: --- step exp N.Foo .0. (full_trace.carbon:[[@LINE-213]]) --->
+// CHECK:STDOUT: (-) stack-pop: N.Foo .0.
+// CHECK:STDOUT: (+) stack-push: Foo .0.
+// CHECK:STDOUT: --- step exp Foo .0. (full_trace.carbon:[[@LINE-216]]) --->
+// CHECK:STDOUT: (-) stack-pop: Foo .0.
+// CHECK:STDOUT: (-) stack-pop: N.Foo .1. {{[[][[]}}fun<N.Foo>]]
+// CHECK:STDOUT: --- step exp N.Foo(0) .1. (full_trace.carbon:[[@LINE-219]]) --->
+// CHECK:STDOUT: (+) stack-push: (0) .0.
+// CHECK:STDOUT: --- step exp (0) .0. (full_trace.carbon:[[@LINE-221]]) --->
+// CHECK:STDOUT: (+) stack-push: 0 .0.
+// CHECK:STDOUT: --- step exp 0 .0. (full_trace.carbon:[[@LINE-223]]) --->
+// CHECK:STDOUT: (-) stack-pop: 0 .0.
+// CHECK:STDOUT: --- step exp (0) .1. (full_trace.carbon:[[@LINE-225]]) --->
+// CHECK:STDOUT: (-) stack-pop: (0) .1. {{[[][[]}}0]]
+// CHECK:STDOUT: --- step exp N.Foo(0) .2. (full_trace.carbon:[[@LINE-227]]) --->
 // CHECK:STDOUT: calling function: fun<N.Foo>
 // CHECK:STDOUT: match pattern (Placeholder<n>,)
 // CHECK:STDOUT: from value expression with value (0,)
 // CHECK:STDOUT: match pattern Placeholder<n>
 // CHECK:STDOUT: from value expression with value 0
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: {return (n + 1);} .0. ## .0. {n: i32: lval<Allocation(1)>} ## N.Foo(0) .3. {{[[][[]}}fun<N.Foo>, (0,)]] {} ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: 0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step stmt {return (n + 1);} .0. (full_trace.carbon:[[@LINE-314]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: return (n + 1); .0. ## {return (n + 1);} .1. {} ## .0. {n: i32: lval<Allocation(1)>} ## N.Foo(0) .3. {{[[][[]}}fun<N.Foo>, (0,)]] {} ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: 0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step stmt return (n + 1); .0. (full_trace.carbon:[[@LINE-321]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: (n + 1) .0. ## return (n + 1); .1. ## {return (n + 1);} .1. {} ## .0. {n: i32: lval<Allocation(1)>} ## N.Foo(0) .3. {{[[][[]}}fun<N.Foo>, (0,)]] {} ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: 0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: (n + 1) .0. ## (n + 1) .1. ## return (n + 1); .1. ## {return (n + 1);} .1. {} ## .0. {n: i32: lval<Allocation(1)>} ## N.Foo(0) .3. {{[[][[]}}fun<N.Foo>, (0,)]] {} ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: 0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step exp (n + 1) .0. (full_trace.carbon:[[@LINE-330]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: n .0. ## (n + 1) .1. ## (n + 1) .1. ## return (n + 1); .1. ## {return (n + 1);} .1. {} ## .0. {n: i32: lval<Allocation(1)>} ## N.Foo(0) .3. {{[[][[]}}fun<N.Foo>, (0,)]] {} ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: 0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: n .0. ## n .1. ## (n + 1) .1. ## (n + 1) .1. ## return (n + 1); .1. ## {return (n + 1);} .1. {} ## .0. {n: i32: lval<Allocation(1)>} ## N.Foo(0) .3. {{[[][[]}}fun<N.Foo>, (0,)]] {} ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: 0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step exp n .0. (full_trace.carbon:[[@LINE-339]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: n .1. {{[[][[]}}0]] ## (n + 1) .1. ## (n + 1) .1. ## return (n + 1); .1. ## {return (n + 1);} .1. {} ## .0. {n: i32: lval<Allocation(1)>} ## N.Foo(0) .3. {{[[][[]}}fun<N.Foo>, (0,)]] {} ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: 0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: (n + 1) .1. {{[[][[]}}0]] ## (n + 1) .1. ## return (n + 1); .1. ## {return (n + 1);} .1. {} ## .0. {n: i32: lval<Allocation(1)>} ## N.Foo(0) .3. {{[[][[]}}fun<N.Foo>, (0,)]] {} ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: 0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step exp (n + 1) .1. (full_trace.carbon:[[@LINE-348]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: 1 .0. ## (n + 1) .2. {{[[][[]}}0]] ## (n + 1) .1. ## return (n + 1); .1. ## {return (n + 1);} .1. {} ## .0. {n: i32: lval<Allocation(1)>} ## N.Foo(0) .3. {{[[][[]}}fun<N.Foo>, (0,)]] {} ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: 0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: 1 .0. ## 1 .1. ## (n + 1) .2. {{[[][[]}}0]] ## (n + 1) .1. ## return (n + 1); .1. ## {return (n + 1);} .1. {} ## .0. {n: i32: lval<Allocation(1)>} ## N.Foo(0) .3. {{[[][[]}}fun<N.Foo>, (0,)]] {} ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: 0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step exp 1 .0. (full_trace.carbon:[[@LINE-357]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: 1 .1. {{[[][[]}}1]] ## (n + 1) .2. {{[[][[]}}0]] ## (n + 1) .1. ## return (n + 1); .1. ## {return (n + 1);} .1. {} ## .0. {n: i32: lval<Allocation(1)>} ## N.Foo(0) .3. {{[[][[]}}fun<N.Foo>, (0,)]] {} ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: 0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: (n + 1) .2. {{[[][[]}}0, 1]] ## (n + 1) .1. ## return (n + 1); .1. ## {return (n + 1);} .1. {} ## .0. {n: i32: lval<Allocation(1)>} ## N.Foo(0) .3. {{[[][[]}}fun<N.Foo>, (0,)]] {} ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: 0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step exp (n + 1) .2. (full_trace.carbon:[[@LINE-366]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: (n + 1) .1. {{[[][[]}}1]] ## return (n + 1); .1. ## {return (n + 1);} .1. {} ## .0. {n: i32: lval<Allocation(1)>} ## N.Foo(0) .3. {{[[][[]}}fun<N.Foo>, (0,)]] {} ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: 0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: return (n + 1); .1. {{[[][[]}}1]] ## {return (n + 1);} .1. {} ## .0. {n: i32: lval<Allocation(1)>} ## N.Foo(0) .3. {{[[][[]}}fun<N.Foo>, (0,)]] {} ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: 0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step stmt return (n + 1); .1. (full_trace.carbon:[[@LINE-375]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: clean up.0. {} ## clean up.0. {n: i32: lval<Allocation(1)>} ## N.Foo(0) .3. {{[[][[]}}fun<N.Foo>, (0,), 1]] {} ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: 0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: clean up.0. {n: i32: lval<Allocation(1)>} ## N.Foo(0) .3. {{[[][[]}}fun<N.Foo>, (0,), 1]] {} ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: 0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: destroy.0. ## clean up.1. {n: i32: lval<Allocation(1)>} ## N.Foo(0) .3. {{[[][[]}}fun<N.Foo>, (0,), 1]] {} ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: 0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: clean up.1. {n: i32: lval<Allocation(1)>} ## N.Foo(0) .3. {{[[][[]}}fun<N.Foo>, (0,), 1]] {} ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: 0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: clean up.2. {n: i32: lval<Allocation(1)>} ## N.Foo(0) .3. {{[[][[]}}fun<N.Foo>, (0,), 1]] {} ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: !!0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: N.Foo(0) .3. {{[[][[]}}fun<N.Foo>, (0,), 1]] {} ## N.Foo(0) .1. ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: !!0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step exp N.Foo(0) .3. (full_trace.carbon:[[@LINE-395]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: clean up.0. {} ## N.Foo(0) .1. {{[[][[]}}1]] ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: !!0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: N.Foo(0) .1. {{[[][[]}}1]] ## return N.Foo(0); .1. ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: !!0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: return N.Foo(0); .1. {{[[][[]}}1]] ## {return N.Foo(0);} .1. {} ## .0. {} ## Main() .3. {{[[][[]}}fun<Main>, ()]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: !!0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: --- step stmt return N.Foo(0); .1. (full_trace.carbon:[[@LINE-408]]) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: clean up.0. {} ## clean up.0. {} ## Main() .3. {{[[][[]}}fun<Main>, (), 1]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: !!0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: clean up.0. {} ## Main() .3. {{[[][[]}}fun<Main>, (), 1]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: !!0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: Main() .3. {{[[][[]}}fun<Main>, (), 1]] {} ## Main() .1.
-// CHECK:STDOUT: memory: 0: Heap{}, 1: !!0
-// CHECK:STDOUT: }
+// CHECK:STDOUT: (+) memory-alloc: #2 `0`
+// CHECK:STDOUT: (+) stack-push: .0. {n: i32: lval<Allocation(2)>}
+// CHECK:STDOUT: (+) stack-push: {return (n + 1);} .0.
+// CHECK:STDOUT: --- step stmt {return (n + 1);} .0. (full_trace.carbon:[[@LINE-239]]) --->
+// CHECK:STDOUT: (+) stack-push: return (n + 1); .0.
+// CHECK:STDOUT: --- step stmt return (n + 1); .0. (full_trace.carbon:[[@LINE-243]]) --->
+// CHECK:STDOUT: (+) stack-push: (n + 1) .0.
+// CHECK:STDOUT: (+) stack-push: (n + 1) .0.
+// CHECK:STDOUT: --- step exp (n + 1) .0. (full_trace.carbon:[[@LINE-246]]) --->
+// CHECK:STDOUT: (+) stack-push: n .0.
+// CHECK:STDOUT: (+) stack-push: n .0.
+// CHECK:STDOUT: --- step exp n .0. (full_trace.carbon:[[@LINE-249]]) --->
+// CHECK:STDOUT: +++ memory-read: #2 `0`
+// CHECK:STDOUT: (-) stack-pop: n .0.
+// CHECK:STDOUT: (-) stack-pop: n .1. {{[[][[]}}0]]
+// CHECK:STDOUT: --- step exp (n + 1) .1. (full_trace.carbon:[[@LINE-253]]) --->
+// CHECK:STDOUT: (+) stack-push: 1 .0.
+// CHECK:STDOUT: (+) stack-push: 1 .0.
+// CHECK:STDOUT: --- step exp 1 .0. (full_trace.carbon:[[@LINE-256]]) --->
+// CHECK:STDOUT: (-) stack-pop: 1 .0.
+// CHECK:STDOUT: (-) stack-pop: 1 .1. {{[[][[]}}1]]
+// CHECK:STDOUT: --- step exp (n + 1) .2. (full_trace.carbon:[[@LINE-259]]) --->
+// CHECK:STDOUT: (-) stack-pop: (n + 1) .2. {{[[][[]}}0, 1]]
+// CHECK:STDOUT: (-) stack-pop: (n + 1) .1. {{[[][[]}}1]]
+// CHECK:STDOUT: --- step stmt return (n + 1); .1. (full_trace.carbon:[[@LINE-262]]) --->
+// CHECK:STDOUT: +++ memory-write: #1 `1`
+// CHECK:STDOUT: (-) stack-pop: return (n + 1); .1. {{[[][[]}}1]]
+// CHECK:STDOUT: (-) stack-pop: {return (n + 1);} .1. {}
+// CHECK:STDOUT: (-) stack-pop: .0. {n: i32: lval<Allocation(2)>}
+// CHECK:STDOUT: (+) stack-push: clean up.0. {n: i32: lval<Allocation(2)>}
+// CHECK:STDOUT: (+) stack-push: clean up.0. {}
+// CHECK:STDOUT: (-) stack-pop: clean up.0. {}
+// CHECK:STDOUT: +++ memory-read: #2 `0`
+// CHECK:STDOUT: (+) stack-push: destroy.0.
+// CHECK:STDOUT: (-) stack-pop: destroy.0.
+// CHECK:STDOUT: (-) memory-dealloc: #2 `0`
+// CHECK:STDOUT: (-) stack-pop: clean up.2. {n: i32: lval<Allocation(2)>}
+// CHECK:STDOUT: --- step exp N.Foo(0) .3. (full_trace.carbon:[[@LINE-270]]) --->
+// CHECK:STDOUT: (-) stack-pop: N.Foo(0) .3. {{[[][[]}}fun<N.Foo>, (0,), 1]] {}
+// CHECK:STDOUT: (+) stack-push: clean up.0. {}
+// CHECK:STDOUT: (-) stack-pop: clean up.0. {}
+// CHECK:STDOUT: --- step stmt var x: i32 = N.Foo(0); .1. (full_trace.carbon:[[@LINE-274]]) --->
+// CHECK:STDOUT: +++ memory-read: #1 `1`
+// CHECK:STDOUT: match pattern Placeholder<x>
+// CHECK:STDOUT: from initializing expression with value 1
+// CHECK:STDOUT: (-) stack-pop: var x: i32 = N.Foo(0); .1. {{[[][[]}}1]]
+// CHECK:STDOUT: --- step stmt {var x: i32 = N.Foo(0);return x;} .1. (full_trace.carbon:[[@LINE+33]]) --->
+// CHECK:STDOUT: (+) stack-push: return x; .0.
+// CHECK:STDOUT: --- step stmt return x; .0. (full_trace.carbon:[[@LINE-280]]) --->
+// CHECK:STDOUT: (+) stack-push: x .0.
+// CHECK:STDOUT: (+) stack-push: x .0.
+// CHECK:STDOUT: --- step exp x .0. (full_trace.carbon:[[@LINE-283]]) --->
+// CHECK:STDOUT: +++ memory-read: #1 `1`
+// CHECK:STDOUT: (-) stack-pop: x .0.
+// CHECK:STDOUT: (-) stack-pop: x .1. {{[[][[]}}ref_expr<Allocation(1)>]]
+// CHECK:STDOUT: --- step stmt return x; .1. (full_trace.carbon:[[@LINE-287]]) --->
+// CHECK:STDOUT: (-) stack-pop: return x; .1. {{[[][[]}}1]]
+// CHECK:STDOUT: (-) stack-pop: {var x: i32 = N.Foo(0);return x;} .2. {x: i32: lval<Allocation(1)>}
+// CHECK:STDOUT: (-) stack-pop: .0. {}
+// CHECK:STDOUT: (+) stack-push: clean up.0. {}
+// CHECK:STDOUT: (+) stack-push: clean up.0. {x: i32: lval<Allocation(1)>}
+// CHECK:STDOUT: +++ memory-read: #1 `1`
+// CHECK:STDOUT: (+) stack-push: destroy.0.
+// CHECK:STDOUT: (-) stack-pop: destroy.0.
+// CHECK:STDOUT: (-) memory-dealloc: #1 `1`
+// CHECK:STDOUT: (-) stack-pop: clean up.2. {x: i32: lval<Allocation(1)>}
+// CHECK:STDOUT: (-) stack-pop: clean up.0. {}
 // CHECK:STDOUT: --- step exp Main() .3. (<Main()>:0) --->
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: clean up.0. {} ## Main() .1. {{[[][[]}}1]]
-// CHECK:STDOUT: memory: 0: Heap{}, 1: !!0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack: Main() .1. {{[[][[]}}1]]
-// CHECK:STDOUT: memory: 0: Heap{}, 1: !!0
-// CHECK:STDOUT: }
-// CHECK:STDOUT: {
-// CHECK:STDOUT: stack:{{ }}
-// CHECK:STDOUT: memory: 0: Heap{}, 1: !!0
-// CHECK:STDOUT: }
+// CHECK:STDOUT: (-) stack-pop: Main() .3. {{[[][[]}}fun<Main>, (), 1]] {}
+// CHECK:STDOUT: (+) stack-push: clean up.0. {}
+// CHECK:STDOUT: (-) stack-pop: clean up.0. {}
+// CHECK:STDOUT: (-) stack-pop: Main() .1. {{[[][[]}}1]]
 // CHECK:STDOUT: interpreter result: 1
 // CHECK:STDOUT: ********** printing timing **********
 // CHECK:STDOUT: Time elapsed in ExecProgram: {{[0-9]+}}ms