diff --git a/ASTPlayground/MainForm.pas b/ASTPlayground/MainForm.pas
index 69b7c05..7d3c968 100644
--- a/ASTPlayground/MainForm.pas
+++ b/ASTPlayground/MainForm.pas
@@ -145,6 +145,7 @@ begin
     Memo1.Lines.Add('');
     Memo1.Lines.Add('');
     Memo1.Lines.Add('--- Recursive fib with AST---');
+    Application.ProcessMessages; // Update UI before blocking
 
     sw.Start;
     root :=
diff --git a/Src/AST/Myc.Ast.Evaluator.pas b/Src/AST/Myc.Ast.Evaluator.pas
index 0ca3c76..d644680 100644
--- a/Src/AST/Myc.Ast.Evaluator.pas
+++ b/Src/AST/Myc.Ast.Evaluator.pas
@@ -38,6 +38,7 @@ type
         procedure Indent;
         procedure Unindent;
         procedure AppendLine(const S: string);
+        procedure AppendMultiline(const S: string);
         procedure ShowScope;
     protected
         function CreateVisitorForScope(AScope: TExecutionScope): IAstVisitor; override;
@@ -57,7 +58,8 @@ type
 implementation
 
 uses
-    Myc.Data.Decimal;
+    Myc.Data.Decimal,
+    Myc.Ast.Printer;
 
 type
     // Concrete implementation of the IEvaluatorClosure interface, private to this unit.
@@ -349,6 +351,18 @@ begin
     FLog.Add(pad + S);
 end;
 
+procedure TDebugEvaluatorVisitor.AppendMultiline(const S: string);
+begin
+    var Str := TStringList.Create;
+    try
+        Str.Text := s;
+        for var i := 0 to Str.Count - 1 do
+            AppendLine(Str[i]);
+    finally
+        Str.Free;
+    end;
+end;
+
 procedure TDebugEvaluatorVisitor.ShowScope;
 var
     scopeDump: TArray<string>;
@@ -419,6 +433,11 @@ begin
     AppendLine('LambdaExpr{');
     Indent;
     try
+        var pp: IAstVisitor := TPrettyPrintVisitor.Create(0);
+        pp.VisitLambdaExpression(Node);
+
+        AppendMultiline((pp as TPrettyPrintVisitor).GetResult);
+
         Result := inherited VisitLambdaExpression(Node);
     finally
         Unindent;
diff --git a/Src/AST/Myc.Ast.Printer.pas b/Src/AST/Myc.Ast.Printer.pas
index 226a7c4..f203862 100644
--- a/Src/AST/Myc.Ast.Printer.pas
+++ b/Src/AST/Myc.Ast.Printer.pas
@@ -17,7 +17,7 @@ type
         procedure Unindent;
         procedure AppendLine(const S: string);
     public
-        constructor Create;
+        constructor Create(AIndentLevel: Integer = 0);
         destructor Destroy; override;
         function GetResult: string;
         // IAstVisitor
@@ -40,11 +40,12 @@ uses
 
 { TPrettyPrintVisitor }
 
-constructor TPrettyPrintVisitor.Create;
+constructor TPrettyPrintVisitor.Create(AIndentLevel: Integer);
 begin
     inherited Create;
     FBuilder := TStringBuilder.Create;
     FIndentLevel := 0;
+    FIndentLevel := AIndentLevel;
 end;
 
 destructor TPrettyPrintVisitor.Destroy;
@@ -88,7 +89,7 @@ end;
 
 function TPrettyPrintVisitor.VisitBinaryExpression(const Node: IBinaryExpressionNode): TAstValue;
 begin
-    AppendLine(Format('BinaryExpr (%s)', [Node.Operator.ToString]));
+    AppendLine(Format('BinaryExpr "%s"', [Node.Operator.ToString]));
     Indent;
     Node.Left.Accept(Self);
     Node.Right.Accept(Self);
@@ -98,7 +99,7 @@ end;
 
 function TPrettyPrintVisitor.VisitUnaryExpression(const Node: IUnaryExpressionNode): TAstValue;
 begin
-    AppendLine(Format('UnaryExpr (%s)', [Node.Operator.ToString]));
+    AppendLine(Format('UnaryExpr "%s"', [Node.Operator.ToString]));
     Indent;
     Node.Right.Accept(Self);
     Unindent;