diff --git a/ASTPlayground/ASTPlayground.dpr b/ASTPlayground/ASTPlayground.dpr
index 347f1c1..60bf9cf 100644
--- a/ASTPlayground/ASTPlayground.dpr
+++ b/ASTPlayground/ASTPlayground.dpr
@@ -5,7 +5,9 @@ uses
     FMX.Forms,
     MainForm in 'MainForm.pas' {Form1},
     Myc.Ast.Evaluator in '..\Src\AST\Myc.Ast.Evaluator.pas',
-    Myc.Ast.Printer in '..\Src\AST\Myc.Ast.Printer.pas';
+    Myc.Ast.Printer in '..\Src\AST\Myc.Ast.Printer.pas',
+    Myc.Ast.Nodes in '..\Src\AST\Myc.Ast.Nodes.pas',
+    Myc.Ast.Scope in '..\Src\AST\Myc.Ast.Scope.pas';
 
 {$R *.res}
 
diff --git a/ASTPlayground/ASTPlayground.dproj b/ASTPlayground/ASTPlayground.dproj
index 650a013..9525b4b 100644
--- a/ASTPlayground/ASTPlayground.dproj
+++ b/ASTPlayground/ASTPlayground.dproj
@@ -137,6 +137,8 @@
         </DCCReference>
         <DCCReference Include="..\Src\AST\Myc.Ast.Evaluator.pas"/>
         <DCCReference Include="..\Src\AST\Myc.Ast.Printer.pas"/>
+        <DCCReference Include="..\Src\AST\Myc.Ast.Nodes.pas"/>
+        <DCCReference Include="..\Src\AST\Myc.Ast.Scope.pas"/>
         <BuildConfiguration Include="Base">
             <Key>Base</Key>
         </BuildConfiguration>
diff --git a/ASTPlayground/MainForm.fmx b/ASTPlayground/MainForm.fmx
index 2aae761..cdedafb 100644
--- a/ASTPlayground/MainForm.fmx
+++ b/ASTPlayground/MainForm.fmx
@@ -8,7 +8,6 @@ object Form1: TForm1
   FormFactor.Height = 480
   FormFactor.Devices = [Desktop]
   OnCreate = FormCreate
-  OnDestroy = FormDestroy
   DesignerMasterStyle = 0
   object Panel1: TPanel
     Align = Left
diff --git a/ASTPlayground/MainForm.pas b/ASTPlayground/MainForm.pas
index 0fefc3b..42f9c60 100644
--- a/ASTPlayground/MainForm.pas
+++ b/ASTPlayground/MainForm.pas
@@ -19,6 +19,7 @@ uses
     FMX.Memo,
     FMX.Controls.Presentation,
     Myc.Data.POD,
+    Myc.Ast.Nodes,
     Myc.Ast,
     Myc.Ast.Evaluator,
     Myc.Ast.Printer; // Added for TExecutionScope
@@ -37,7 +38,6 @@ type
         CrerateTriggerExampleButton: TButton;
         DoTriggerButton: TButton;
         DoTrigger2Button: TButton;
-        procedure FormDestroy(Sender: TObject);
         procedure FormCreate(Sender: TObject);
         procedure CrerateTriggerExampleButtonClick(Sender: TObject);
         procedure DebugButtonClick(Sender: TObject);
@@ -51,7 +51,7 @@ type
     private
         // Stores the last AST generated by Test1 or Test2 button clicks.
         FLastAst: IAstNode;
-        FGScope: TExecutionScope;
+        FGScope: IExecutionScope;
     public
     { Public declarations }
     end;
@@ -62,23 +62,19 @@ var
 implementation
 
 uses
+    Myc.Ast.Scope,
     System.Diagnostics; // For TStopwatch
 
 {$R *.fmx}
 
-procedure TForm1.FormDestroy(Sender: TObject);
-begin
-    FGScope.Free;
-end;
-
 procedure TForm1.FormCreate(Sender: TObject);
 begin
-    FGScope := TExecutionScope.Create(nil);
+    FGScope := T_ExecutionScope.Create(nil);
 end;
 
 procedure TForm1.DebugButtonClick(Sender: TObject);
 var
-    scope: TExecutionScope;
+    scope: IExecutionScope;
     visitor: IAstVisitor;
     result: TAstValue;
     sw: TStopwatch;
@@ -90,26 +86,22 @@ begin
         exit;
     end;
 
-    scope := TExecutionScope.Create(FGScope);
-    try
-        Memo1.Lines.Clear;
-        Memo1.Lines.Add('--- Debug Evaluator Trace ---');
+    scope := T_ExecutionScope.Create(FGScope);
 
-        visitor := TDebugEvaluatorVisitor.Create(scope, Memo1.Lines, ShowScopeBox.IsChecked, 0);
+    Memo1.Lines.Clear;
+    Memo1.Lines.Add('--- Debug Evaluator Trace ---');
 
-        sw := TStopwatch.StartNew;
-        result := FLastAst.Accept(visitor);
-        sw.Stop;
+    visitor := TDebugEvaluatorVisitor.Create(scope, Memo1.Lines, ShowScopeBox.IsChecked, 0);
 
-        Memo1.Lines.Add('-----------------------------');
-        Memo1.Lines.Add(Format('Final script result: %s', [result.ToString]));
-        Memo1.Lines.Add(Format('Execution time: %d ms', [sw.ElapsedMilliseconds]));
-        Memo1.Lines.Add('');
-        Memo1.Lines.Add('(AST structure stored. Click "Pretty Print" to view.)');
+    sw := TStopwatch.StartNew;
+    result := FLastAst.Accept(visitor);
+    sw.Stop;
 
-    finally
-        scope.Free;
-    end;
+    Memo1.Lines.Add('-----------------------------');
+    Memo1.Lines.Add(Format('Final script result: %s', [result.ToString]));
+    Memo1.Lines.Add(Format('Execution time: %d ms', [sw.ElapsedMilliseconds]));
+    Memo1.Lines.Add('');
+    Memo1.Lines.Add('(AST structure stored. Click "Pretty Print" to view.)');
 end;
 
 procedure TForm1.FibonacciButtonClick(Sender: TObject);
@@ -124,7 +116,7 @@ procedure TForm1.FibonacciButtonClick(Sender: TObject);
     end;
 
 var
-    scope: TExecutionScope;
+    scope: IExecutionScope;
     visitor: IAstVisitor;
     root: IExpressionNode;
     result: TAstValue;
@@ -198,18 +190,15 @@ begin
         );
 
     FLastAst := root;
-    scope := TExecutionScope.Create(nil);
-    try
-        visitor := TEvaluatorVisitor.Create(scope);
-        result := root.Accept(visitor);
-        sw.Stop;
+    scope := T_ExecutionScope.Create(nil);
 
-        Memo1.Lines.Add(Format('Result: fib(30) %s (calculated in %d ms)', [result.ToString, sw.ElapsedMilliseconds]));
-        Memo1.Lines.Add('');
-        Memo1.Lines.Add('(AST structure stored. Click "Pretty Print" or "Debug" to view.)');
-    finally
-        scope.Free;
-    end;
+    visitor := TEvaluatorVisitor.Create(scope);
+    result := root.Accept(visitor);
+    sw.Stop;
+
+    Memo1.Lines.Add(Format('Result: fib(30) %s (calculated in %d ms)', [result.ToString, sw.ElapsedMilliseconds]));
+    Memo1.Lines.Add('');
+    Memo1.Lines.Add('(AST structure stored. Click "Pretty Print" or "Debug" to view.)');
 end;
 
 procedure TForm1.PrettyPrintButtonClick(Sender: TObject);
@@ -242,7 +231,7 @@ end;
 
 procedure TForm1.RecursionButtonClick(Sender: TObject);
 var
-    scope: TExecutionScope;
+    scope: IExecutionScope;
     visitor: IAstVisitor;
     root: IExpressionNode;
     result: TAstValue;
@@ -281,24 +270,21 @@ begin
         );
 
     FLastAst := root;
-    scope := TExecutionScope.Create(nil);
-    try
-        visitor := TEvaluatorVisitor.Create(scope);
-        result := root.Accept(visitor);
-        sw.Stop;
+    scope := T_ExecutionScope.Create(nil);
 
-        Memo1.Lines.Add(Format('Result: %s (calculated in %d ms)', [result.ToString, sw.ElapsedMilliseconds]));
-        Memo1.Lines.Add('');
-        Memo1.Lines.Add('(AST structure stored. Click "Pretty Print" or "Debug" to view.)');
-    finally
-        scope.Free;
-    end;
+    visitor := TEvaluatorVisitor.Create(scope);
+    result := root.Accept(visitor);
+    sw.Stop;
+
+    Memo1.Lines.Add(Format('Result: %s (calculated in %d ms)', [result.ToString, sw.ElapsedMilliseconds]));
+    Memo1.Lines.Add('');
+    Memo1.Lines.Add('(AST structure stored. Click "Pretty Print" or "Debug" to view.)');
 end;
 
 procedure TForm1.Test1ButtonClick(Sender: TObject);
 var
     root: IAstNode;
-    scope: TExecutionScope;
+    scope: IExecutionScope;
     visitor: IAstVisitor;
     result: TAstValue;
     sw: TStopwatch;
@@ -320,26 +306,23 @@ begin
         );
 
     FLastAst := root;
-    scope := TExecutionScope.Create(nil);
-    try
-        visitor := TEvaluatorVisitor.Create(scope);
-        result := root.Accept(visitor);
-        sw.Stop;
+    scope := T_ExecutionScope.Create(FGScope);
 
-        if not result.IsUndefined then
-            Memo1.Lines.Add(Format('Result: %s (calculated in %d ms)', [result.ToString, sw.ElapsedMilliseconds]))
-        else
-            Memo1.Lines.Add(Format('<undefined result> (calculated in %d ms)', [sw.ElapsedMilliseconds]));
-        Memo1.Lines.Add('');
-        Memo1.Lines.Add('(AST structure stored. Click "Pretty Print" to view.)');
-    finally
-        scope.Free;
-    end;
+    visitor := TEvaluatorVisitor.Create(scope);
+    result := root.Accept(visitor);
+    sw.Stop;
+
+    if not result.IsUndefined then
+        Memo1.Lines.Add(Format('Result: %s (calculated in %d ms)', [result.ToString, sw.ElapsedMilliseconds]))
+    else
+        Memo1.Lines.Add(Format('<undefined result> (calculated in %d ms)', [sw.ElapsedMilliseconds]));
+    Memo1.Lines.Add('');
+    Memo1.Lines.Add('(AST structure stored. Click "Pretty Print" to view.)');
 end;
 
 procedure TForm1.Test2ButtonClick(Sender: TObject);
 var
-    scope: TExecutionScope;
+    scope: IExecutionScope;
     visitor: IAstVisitor;
     root: IExpressionNode;
     result: TAstValue;
@@ -373,19 +356,17 @@ begin
         );
 
     FLastAst := root;
-    scope := TExecutionScope.Create(nil);
-    try
-        visitor := TEvaluatorVisitor.Create(scope);
-        result := root.Accept(visitor);
-        sw.Stop;
 
-        Memo1.Lines.Add('The entire script has been executed.');
-        Memo1.Lines.Add(Format('Result of the final expression: %s (calculated in %d ms)', [result.ToString, sw.ElapsedMilliseconds]));
-        Memo1.Lines.Add('');
-        Memo1.Lines.Add('(AST structure stored. Click "Pretty Print" to view.)');
-    finally
-        scope.Free;
-    end;
+    scope := T_ExecutionScope.Create(FGScope);
+
+    visitor := TEvaluatorVisitor.Create(scope);
+    result := root.Accept(visitor);
+    sw.Stop;
+
+    Memo1.Lines.Add('The entire script has been executed.');
+    Memo1.Lines.Add(Format('Result of the final expression: %s (calculated in %d ms)', [result.ToString, sw.ElapsedMilliseconds]));
+    Memo1.Lines.Add('');
+    Memo1.Lines.Add('(AST structure stored. Click "Pretty Print" to view.)');
 end;
 
 procedure TForm1.CrerateTriggerExampleButtonClick(Sender: TObject);
diff --git a/Src/AST/Myc.Ast.Evaluator.pas b/Src/AST/Myc.Ast.Evaluator.pas
index 06876a4..5386475 100644
--- a/Src/AST/Myc.Ast.Evaluator.pas
+++ b/Src/AST/Myc.Ast.Evaluator.pas
@@ -7,18 +7,19 @@ uses
     System.Classes, // For TStrings
     System.Generics.Collections,
     Myc.Data.POD,
+    Myc.Ast.Nodes,
     Myc.Ast;
 
 type
     // TEvaluatorVisitor is the base implementation for evaluating an AST.
     TEvaluatorVisitor = class(TInterfacedObject, IAstVisitor)
     private
-        FScope: TExecutionScope;
+        FScope: IExecutionScope;
     protected
         function IsTruthy(const AValue: TAstValue): Boolean;
-        function CreateVisitorForScope(AScope: TExecutionScope): IAstVisitor; virtual;
+        function CreateVisitorForScope(const AScope: IExecutionScope): IAstVisitor; virtual;
     public
-        constructor Create(AScope: TExecutionScope);
+        constructor Create(const AScope: IExecutionScope);
         function VisitConstant(const Node: IConstantNode): TAstValue; virtual;
         function VisitIdentifier(const Node: IIdentifierNode): TAstValue; virtual;
         function VisitBinaryExpression(const Node: IBinaryExpressionNode): TAstValue; virtual;
@@ -43,9 +44,9 @@ type
         procedure AppendMultiline(const S: string);
         procedure ShowScope;
     protected
-        function CreateVisitorForScope(AScope: TExecutionScope): IAstVisitor; override;
+        function CreateVisitorForScope(const AScope: IExecutionScope): IAstVisitor; override;
     public
-        constructor Create(AScope: TExecutionScope; ALog: TStrings; AShowScope: Boolean; AInitialIndent: Integer = 0);
+        constructor Create(const AScope: IExecutionScope; ALog: TStrings; AShowScope: Boolean; AInitialIndent: Integer = 0);
         function VisitConstant(const Node: IConstantNode): TAstValue; override;
         function VisitIdentifier(const Node: IIdentifierNode): TAstValue; override;
         function VisitBinaryExpression(const Node: IBinaryExpressionNode): TAstValue; override;
@@ -62,6 +63,7 @@ implementation
 
 uses
     Myc.Data.Decimal,
+    Myc.Ast.Scope,
     Myc.Ast.Printer;
 
 type
@@ -70,17 +72,17 @@ type
     private
         FBody: IExpressionNode;
         FParameters: TArray<IIdentifierNode>;
-        FClosureScope: TExecutionScope;
+        FClosureScope: IExecutionScope;
         function GetBody: IExpressionNode;
         function GetParameters: TArray<IIdentifierNode>;
-        function GetClosureScope: TExecutionScope;
+        function GetClosureScope: IExecutionScope;
     public
-        constructor Create(ABody: IExpressionNode; const AParameters: TArray<IIdentifierNode>; AClosureScope: TExecutionScope);
+        constructor Create(ABody: IExpressionNode; const AParameters: TArray<IIdentifierNode>; const AClosureScope: IExecutionScope);
     end;
 
 { TClosureValue }
 
-constructor TClosureValue.Create(ABody: IExpressionNode; const AParameters: TArray<IIdentifierNode>; AClosureScope: TExecutionScope);
+constructor TClosureValue.Create(ABody: IExpressionNode; const AParameters: TArray<IIdentifierNode>; const AClosureScope: IExecutionScope);
 begin
     inherited Create;
     FBody := ABody;
@@ -93,7 +95,7 @@ begin
     Result := FBody;
 end;
 
-function TClosureValue.GetClosureScope: TExecutionScope;
+function TClosureValue.GetClosureScope: IExecutionScope;
 begin
     Result := FClosureScope;
 end;
@@ -105,14 +107,14 @@ end;
 
 { TEvaluatorVisitor }
 
-constructor TEvaluatorVisitor.Create(AScope: TExecutionScope);
+constructor TEvaluatorVisitor.Create(const AScope: IExecutionScope);
 begin
     inherited Create;
     Assert(Assigned(AScope));
     FScope := AScope;
 end;
 
-function TEvaluatorVisitor.CreateVisitorForScope(AScope: TExecutionScope): IAstVisitor;
+function TEvaluatorVisitor.CreateVisitorForScope(const AScope: IExecutionScope): IAstVisitor;
 begin
     Result := TEvaluatorVisitor.Create(AScope);
 end;
@@ -192,7 +194,7 @@ var
     calleeValue: TAstValue;
     arguments: TList<IExpressionNode>;
     closure: IEvaluatorClosure;
-    callScope: TExecutionScope;
+    callScope: IExecutionScope;
     innerVisitor: IAstVisitor;
     i: Integer;
     argValue: TAstValue;
@@ -211,19 +213,16 @@ begin
         raise EArgumentException.CreateFmt('Argument count mismatch: expected %d, got %d', [Length(closure.Parameters), arguments.Count]);
     end;
 
-    callScope := TExecutionScope.Create(closure.ClosureScope);
-    try
-        for i := 0 to arguments.Count - 1 do
-        begin
-            argValue := arguments[i].Accept(Self);
-            callScope.SetValue(closure.Parameters[i].Name, argValue);
-        end;
+    callScope := T_ExecutionScope.Create(closure.ClosureScope);
 
-        innerVisitor := Self.CreateVisitorForScope(callScope);
-        Result := closure.Body.Accept(innerVisitor);
-    finally
-        callScope.Free;
+    for i := 0 to arguments.Count - 1 do
+    begin
+        argValue := arguments[i].Accept(Self);
+        callScope.SetValue(closure.Parameters[i].Name, argValue);
     end;
+
+    innerVisitor := Self.CreateVisitorForScope(callScope);
+    Result := closure.Body.Accept(innerVisitor);
 end;
 
 function TEvaluatorVisitor.VisitBinaryExpression(const Node: IBinaryExpressionNode): TAstValue;
@@ -332,17 +331,18 @@ end;
 
 { TDebugEvaluatorVisitor }
 
-constructor TDebugEvaluatorVisitor.Create(AScope: TExecutionScope; ALog: TStrings; AShowScope: Boolean; AInitialIndent: Integer);
+constructor TDebugEvaluatorVisitor.Create(const AScope: IExecutionScope; ALog: TStrings; AShowScope: Boolean; AInitialIndent: Integer = 0);
 begin
     inherited Create(AScope);
     Assert(Assigned(ALog));
     FLog := ALog;
     FIndentLevel := AInitialIndent;
     FShowScope := AShowScope;
+
     ShowScope;
 end;
 
-function TDebugEvaluatorVisitor.CreateVisitorForScope(AScope: TExecutionScope): IAstVisitor;
+function TDebugEvaluatorVisitor.CreateVisitorForScope(const AScope: IExecutionScope): IAstVisitor;
 begin
     Result := TDebugEvaluatorVisitor.Create(AScope, FLog, FShowScope, FIndentLevel);
 end;
diff --git a/Src/AST/Myc.Ast.Nodes.pas b/Src/AST/Myc.Ast.Nodes.pas
new file mode 100644
index 0000000..a31e763
--- /dev/null
+++ b/Src/AST/Myc.Ast.Nodes.pas
@@ -0,0 +1,305 @@
+unit Myc.Ast.Nodes;
+
+interface
+
+uses
+    System.SysUtils,
+    System.Generics.Collections,
+    Myc.Data.POD;
+
+type
+    // Operators and helpers
+    TBinaryOperator = (boAdd, boSubtract, boMultiply, boDivide, boEqual, boNotEqual, boLess, boGreater, boLessOrEqual, boGreaterOrEqual);
+    TUnaryOperator = (uoNegate, uoNot);
+
+    TBinaryOperatorHelper = record helper for TBinaryOperator
+        function ToString: string;
+    end;
+
+    TUnaryOperatorHelper = record helper for TUnaryOperator
+        function ToString: string;
+    end;
+
+    TAstValueKind = (avkUndefined, avkScalar, avkClosure);
+
+    // --- Forward Declarations to break cycles ---
+    IExecutionScope = interface;
+    IAstVisitor = interface;
+    IAstNode = interface;
+    IExpressionNode = interface;
+    IIdentifierNode = interface;
+    IConstantNode = interface;
+    IBinaryExpressionNode = interface;
+    IUnaryExpressionNode = interface;
+    IIfExpressionNode = interface;
+    ILambdaExpressionNode = interface;
+    IFunctionCallNode = interface;
+    IBlockExpressionNode = interface;
+    IVariableDeclarationNode = interface;
+    IAssignmentNode = interface;
+    IEvaluatorClosure = interface;
+
+    // --- Concrete Type Definitions ---
+
+    IEvaluatorClosure = interface(IInterface)
+        {$region 'private'}
+        function GetBody: IExpressionNode;
+        function GetParameters: TArray<IIdentifierNode>;
+        function GetClosureScope: IExecutionScope;
+        {$endregion}
+        property Body: IExpressionNode read GetBody;
+        property Parameters: TArray<IIdentifierNode> read GetParameters;
+        property ClosureScope: IExecutionScope read GetClosureScope;
+    end;
+
+    TAstValue = record
+    private
+        FKind: TAstValueKind;
+        FScalar: TScalar;
+        FClosure: IEvaluatorClosure;
+        function GetKind: TAstValueKind; inline;
+        function GetIsScalar: Boolean; inline;
+        function GetIsClosure: Boolean; inline;
+        function GetIsUndefined: Boolean; inline;
+    public
+        class operator Initialize(out Dest: TAstValue);
+        class function Undefined: TAstValue; static;
+        class function FromScalar(const AValue: TScalar): TAstValue; static;
+        class function FromClosure(const AValue: IEvaluatorClosure): TAstValue; static;
+        function AsScalar: TScalar;
+        function AsClosure: IEvaluatorClosure;
+        function ToString: String;
+        property Kind: TAstValueKind read GetKind;
+        property IsScalar: Boolean read GetIsScalar;
+        property IsClosure: Boolean read GetIsClosure;
+        property IsUndefined: Boolean read GetIsUndefined;
+    end;
+
+    IExecutionScope = interface(IInterface)
+        {$region 'private'}
+        function GetParent: IExecutionScope;
+        {$endregion}
+        procedure Clear;
+        function FindValue(const Name: string; out Value: TAstValue): Boolean;
+        procedure SetValue(const Name: string; const Value: TAstValue);
+        procedure AssignValue(const Name: string; const Value: TAstValue);
+        function Dump: string;
+        property Parent: IExecutionScope read GetParent;
+    end;
+
+    IAstVisitor = interface
+        ['{A58B0A8E-F438-4217-A964-6E35624A9A4A}']
+        function VisitConstant(const Node: IConstantNode): TAstValue;
+        function VisitIdentifier(const Node: IIdentifierNode): TAstValue;
+        function VisitBinaryExpression(const Node: IBinaryExpressionNode): TAstValue;
+        function VisitUnaryExpression(const Node: IUnaryExpressionNode): TAstValue;
+        function VisitIfExpression(const Node: IIfExpressionNode): TAstValue;
+        function VisitLambdaExpression(const Node: ILambdaExpressionNode): TAstValue;
+        function VisitFunctionCall(const Node: IFunctionCallNode): TAstValue;
+        function VisitBlockExpression(const Node: IBlockExpressionNode): TAstValue;
+        function VisitVariableDeclaration(const Node: IVariableDeclarationNode): TAstValue;
+        function VisitAssignment(const Node: IAssignmentNode): TAstValue;
+    end;
+
+    IAstNode = interface(IInterface)
+        function Accept(const Visitor: IAstVisitor): TAstValue;
+    end;
+
+    IExpressionNode = interface(IAstNode)
+    end;
+
+    IConstantNode = interface(IExpressionNode)
+        {$region 'private'}
+        function GetValue: TScalar;
+        {$endregion}
+        property Value: TScalar read GetValue;
+    end;
+
+    IIdentifierNode = interface(IExpressionNode)
+        {$region 'private'}
+        function GetName: string;
+        {$endregion}
+        property Name: string read GetName;
+    end;
+
+    IBinaryExpressionNode = interface(IExpressionNode)
+        {$region 'private'}
+        function GetLeft: IExpressionNode;
+        function GetOperator: TBinaryOperator;
+        function GetRight: IExpressionNode;
+        {$endregion}
+        property Left: IExpressionNode read GetLeft;
+        property Operator: TBinaryOperator read GetOperator;
+        property Right: IExpressionNode read GetRight;
+    end;
+
+    IUnaryExpressionNode = interface(IExpressionNode)
+        {$region 'private'}
+        function GetOperator: TUnaryOperator;
+        function GetRight: IExpressionNode;
+        {$endregion}
+        property Operator: TUnaryOperator read GetOperator;
+        property Right: IExpressionNode read GetRight;
+    end;
+
+    IIfExpressionNode = interface(IExpressionNode)
+        {$region 'private'}
+        function GetCondition: IExpressionNode;
+        function GetThenBranch: IExpressionNode;
+        function GetElseBranch: IExpressionNode;
+        {$endregion}
+        property Condition: IExpressionNode read GetCondition;
+        property ThenBranch: IExpressionNode read GetThenBranch;
+        property ElseBranch: IExpressionNode read GetElseBranch;
+    end;
+
+    ILambdaExpressionNode = interface(IExpressionNode)
+        {$region 'private'}
+        function GetParameters: TArray<IIdentifierNode>;
+        function GetBody: IExpressionNode;
+        {$endregion}
+        property Parameters: TArray<IIdentifierNode> read GetParameters;
+        property Body: IExpressionNode read GetBody;
+    end;
+
+    IFunctionCallNode = interface(IExpressionNode)
+        {$region 'private'}
+        function GetCallee: IExpressionNode;
+        function GetArguments: TList<IExpressionNode>;
+        {$endregion}
+        property Callee: IExpressionNode read GetCallee;
+        property Arguments: TList<IExpressionNode> read GetArguments;
+    end;
+
+    IBlockExpressionNode = interface(IExpressionNode)
+        {$region 'private'}
+        function GetExpressions: TList<IExpressionNode>;
+        {$endregion}
+        property Expressions: TList<IExpressionNode> read GetExpressions;
+    end;
+
+    IVariableDeclarationNode = interface(IExpressionNode)
+        {$region 'private'}
+        function GetIdentifier: IIdentifierNode;
+        function GetInitializer: IExpressionNode;
+        {$endregion}
+        property Identifier: IIdentifierNode read GetIdentifier;
+        property Initializer: IExpressionNode read GetInitializer;
+    end;
+
+    IAssignmentNode = interface(IExpressionNode)
+        {$region 'private'}
+        function GetIdentifier: IIdentifierNode;
+        function GetValue: IExpressionNode;
+        {$endregion}
+        property Identifier: IIdentifierNode read GetIdentifier;
+        property Value: IExpressionNode read GetValue;
+    end;
+
+implementation
+
+{ TAstValue }
+
+class operator TAstValue.Initialize(out Dest: TAstValue);
+begin
+    Dest.FKind := avkUndefined;
+    Dest.FClosure := nil;
+end;
+
+function TAstValue.AsClosure: IEvaluatorClosure;
+begin
+    if (FKind <> avkClosure) then
+        raise EInvalidCast.Create('Cannot read value as a Closure.');
+    Result := FClosure;
+end;
+
+function TAstValue.AsScalar: TScalar;
+begin
+    if (FKind <> avkScalar) then
+        raise EInvalidCast.Create('Cannot read value as a Scalar.');
+    Result := FScalar;
+end;
+
+class function TAstValue.FromClosure(const AValue: IEvaluatorClosure): TAstValue;
+begin
+    Result.FKind := avkClosure;
+    Result.FClosure := AValue;
+    Result.FScalar := Default(TScalar);
+end;
+
+class function TAstValue.FromScalar(const AValue: TScalar): TAstValue;
+begin
+    Result.FKind := avkScalar;
+    Result.FScalar := AValue;
+    Result.FClosure := nil;
+end;
+
+function TAstValue.GetIsClosure: Boolean;
+begin
+    Result := FKind = avkClosure;
+end;
+
+function TAstValue.GetIsScalar: Boolean;
+begin
+    Result := FKind = avkScalar;
+end;
+
+function TAstValue.GetIsUndefined: Boolean;
+begin
+    Result := FKind = avkUndefined;
+end;
+
+function TAstValue.GetKind: TAstValueKind;
+begin
+    Result := FKind;
+end;
+
+function TAstValue.ToString: String;
+begin
+    case FKind of
+        avkScalar: Result := FScalar.ToString;
+        avkClosure: Result := '<closure>';
+        avkUndefined: Result := '<void>';
+    else
+        Result := '[Unknown AstValue]';
+    end;
+end;
+
+class function TAstValue.Undefined: TAstValue;
+begin
+    Result := Default(TAstValue);
+end;
+
+{ TBinaryOperatorHelper }
+
+function TBinaryOperatorHelper.ToString: string;
+begin
+    case Self of
+        boAdd: Result := '+';
+        boSubtract: Result := '-';
+        boMultiply: Result := '*';
+        boDivide: Result := '/';
+        boEqual: Result := '==';
+        boNotEqual: Result := '!=';
+        boLess: Result := '<';
+        boGreater: Result := '>';
+        boLessOrEqual: Result := '<=';
+        boGreaterOrEqual: Result := '>=';
+    else
+        Result := '?';
+    end;
+end;
+
+{ TUnaryOperatorHelper }
+
+function TUnaryOperatorHelper.ToString: string;
+begin
+    case Self of
+        uoNegate: Result := '-';
+        uoNot: Result := 'not';
+    else
+        Result := '?';
+    end;
+end;
+
+end.
diff --git a/Src/AST/Myc.Ast.Printer.pas b/Src/AST/Myc.Ast.Printer.pas
index 525d15f..fde1f28 100644
--- a/Src/AST/Myc.Ast.Printer.pas
+++ b/Src/AST/Myc.Ast.Printer.pas
@@ -6,6 +6,7 @@ uses
     System.SysUtils,
     System.Classes,
     System.Generics.Collections,
+    Myc.Ast.Nodes,
     Myc.Ast;
 
 type
diff --git a/Src/AST/Myc.Ast.Scope.pas b/Src/AST/Myc.Ast.Scope.pas
new file mode 100644
index 0000000..3eacf36
--- /dev/null
+++ b/Src/AST/Myc.Ast.Scope.pas
@@ -0,0 +1,123 @@
+unit Myc.Ast.Scope;
+
+interface
+
+uses
+    System.SysUtils,
+    System.Generics.Collections,
+    System.Classes,
+    Myc.Ast.Nodes;
+
+type
+    T_ExecutionScope = class(TInterfacedObject, IExecutionScope)
+    private
+        FParent: IExecutionScope;
+        FVariables: TDictionary<string, TAstValue>;
+        procedure DumpScope(const ABuilder: TStringBuilder; AIndent: Integer);
+    protected
+        // IExecutionScope
+        function GetParent: IExecutionScope;
+        procedure Clear;
+        function FindValue(const Name: string; out Value: TAstValue): Boolean;
+        procedure SetValue(const Name: string; const Value: TAstValue);
+        procedure AssignValue(const Name: string; const Value: TAstValue);
+        function Dump: string;
+    public
+        constructor Create(AParent: IExecutionScope = nil);
+        destructor Destroy; override;
+    end;
+
+implementation
+
+{ T_ExecutionScope }
+
+constructor T_ExecutionScope.Create(AParent: IExecutionScope);
+begin
+    inherited Create;
+    FParent := AParent;
+    FVariables := TDictionary<string, TAstValue>.Create;
+end;
+
+destructor T_ExecutionScope.Destroy;
+begin
+    FVariables.Free;
+    inherited Destroy;
+end;
+
+function T_ExecutionScope.GetParent: IExecutionScope;
+begin
+    Result := FParent;
+end;
+
+procedure T_ExecutionScope.AssignValue(const Name: string; const Value: TAstValue);
+begin
+    if FVariables.ContainsKey(Name) then
+        FVariables.AddOrSetValue(Name, Value)
+    else if Assigned(FParent) then
+        FParent.AssignValue(Name, Value)
+    else
+        raise Exception.CreateFmt('Cannot assign to undeclared variable "%s".', [Name]);
+end;
+
+procedure T_ExecutionScope.Clear;
+begin
+    FVariables.Clear;
+    if Assigned(FParent) then
+        FParent.Clear;
+end;
+
+procedure T_ExecutionScope.DumpScope(const ABuilder: TStringBuilder; AIndent: Integer);
+var
+    pair: TPair<string, TAstValue>;
+    indentStr: string;
+begin
+    indentStr := ''.PadLeft(AIndent);
+    if (FVariables.Count > 0) then
+    begin
+        for pair in FVariables do
+            ABuilder.AppendLine(indentStr + Format('  %s: %s', [pair.Key, pair.Value.ToString]));
+    end
+    else
+    begin
+        ABuilder.AppendLine(indentStr + '  (empty)');
+    end;
+
+    if Assigned(FParent) then
+    begin
+        ABuilder.AppendLine(indentStr + '[Parent Scope]');
+        // As FParent is now an interface, we must cast it back to the class to call the private DumpScope.
+        // This indicates that DumpScope should perhaps be part of the interface or handled differently.
+        // For now, we use a cast to keep the functionality.
+        (FParent as T_ExecutionScope).DumpScope(ABuilder, AIndent + 2);
+    end;
+end;
+
+function T_ExecutionScope.Dump: string;
+var
+    builder: TStringBuilder;
+begin
+    builder := TStringBuilder.Create;
+    try
+        builder.AppendLine('[Current Scope]');
+        DumpScope(builder, 0);
+        Result := builder.ToString.TrimRight;
+    finally
+        builder.Free;
+    end;
+end;
+
+function T_ExecutionScope.FindValue(const Name: string; out Value: TAstValue): Boolean;
+begin
+    Result := FVariables.TryGetValue(Name, Value);
+    if not Result and Assigned(FParent) then
+    begin
+        Result := FParent.FindValue(Name, Value);
+    end;
+end;
+
+procedure T_ExecutionScope.SetValue(const Name: string; const Value: TAstValue);
+begin
+    FVariables.AddOrSetValue(Name, Value);
+end;
+
+end.
diff --git a/Src/AST/Myc.Ast.pas b/Src/AST/Myc.Ast.pas
index 745d1f1..6424c35 100644
--- a/Src/AST/Myc.Ast.pas
+++ b/Src/AST/Myc.Ast.pas
@@ -4,211 +4,10 @@ interface
 
 uses
     System.SysUtils,
-    System.Classes,
-    System.Generics.Collections,
-    Myc.Data.POD;
+    Myc.Data.POD,
+    Myc.Ast.Nodes;
 
 type
-    // Operators are now type-safe enums
-    TBinaryOperator = (boAdd, boSubtract, boMultiply, boDivide, boEqual, boNotEqual, boLess, boGreater, boLessOrEqual, boGreaterOrEqual);
-    TUnaryOperator = (uoNegate, uoNot);
-
-    // Helper to convert operators to string
-    TBinaryOperatorHelper = record helper for TBinaryOperator
-        function ToString: string;
-    end;
-
-    TUnaryOperatorHelper = record helper for TUnaryOperator
-        function ToString: string;
-    end;
-
-    // Defines the kind of value stored in a TAstValue record.
-    TAstValueKind = (
-        avkUndefined, // Represents a void, null or uninitialized value.
-        avkScalar, // The value is a POD scalar (TScalar).
-        avkClosure // The value is a managed closure (IEvaluatorClosure).
-    );
-
-    // --- Forward Declarations to break cycles ---
-    IAstVisitor = interface;
-    IAstNode = interface;
-    IExpressionNode = interface;
-    IIdentifierNode = interface;
-    IConstantNode = interface;
-    IBinaryExpressionNode = interface;
-    IUnaryExpressionNode = interface;
-    IIfExpressionNode = interface;
-    ILambdaExpressionNode = interface;
-    IFunctionCallNode = interface;
-    IBlockExpressionNode = interface;
-    IVariableDeclarationNode = interface;
-    IAssignmentNode = interface; // Represents an assignment to an existing variable.
-    IEvaluatorClosure = interface;
-    TExecutionScope = class;
-
-    // --- Concrete Type Definitions ---
-
-    // Represents a closure value for the TAstValue-based evaluator.
-    IEvaluatorClosure = interface(IInterface)
-        {$region 'private'}
-        function GetBody: IExpressionNode;
-        function GetParameters: TArray<IIdentifierNode>;
-        function GetClosureScope: TExecutionScope;
-        {$endregion}
-        property Body: IExpressionNode read GetBody;
-        property Parameters: TArray<IIdentifierNode> read GetParameters;
-        property ClosureScope: TExecutionScope read GetClosureScope;
-    end;
-
-    // A universal value container for the AST evaluator.
-    TAstValue = record
-    private
-        FKind: TAstValueKind;
-        FScalar: TScalar;
-        FClosure: IEvaluatorClosure;
-
-        function GetKind: TAstValueKind; inline;
-        function GetIsScalar: Boolean; inline;
-        function GetIsClosure: Boolean; inline;
-        function GetIsUndefined: Boolean; inline;
-    public
-        // Managed record operators to handle the lifetime of FObject.
-        class operator Initialize(out Dest: TAstValue);
-        // Factory methods for clean creation.
-        class function Undefined: TAstValue; static;
-        class function FromScalar(const AValue: TScalar): TAstValue; static;
-        class function FromClosure(const AValue: IEvaluatorClosure): TAstValue; static;
-
-        // Accessors for the stored values.
-        function AsScalar: TScalar;
-        function AsClosure: IEvaluatorClosure;
-
-        function ToString: String;
-
-        // Properties for convenient access and type checking.
-        property Kind: TAstValueKind read GetKind;
-        property IsScalar: Boolean read GetIsScalar;
-        property IsClosure: Boolean read GetIsClosure;
-        property IsUndefined: Boolean read GetIsUndefined;
-    end;
-
-    // The visitor pattern interface for traversing the AST.
-    IAstVisitor = interface
-        ['{A58B0A8E-F438-4217-A964-6E35624A9A4A}']
-        function VisitConstant(const Node: IConstantNode): TAstValue;
-        function VisitIdentifier(const Node: IIdentifierNode): TAstValue;
-        function VisitBinaryExpression(const Node: IBinaryExpressionNode): TAstValue;
-        function VisitUnaryExpression(const Node: IUnaryExpressionNode): TAstValue;
-        function VisitIfExpression(const Node: IIfExpressionNode): TAstValue;
-        function VisitLambdaExpression(const Node: ILambdaExpressionNode): TAstValue;
-        function VisitFunctionCall(const Node: IFunctionCallNode): TAstValue;
-        function VisitBlockExpression(const Node: IBlockExpressionNode): TAstValue;
-        function VisitVariableDeclaration(const Node: IVariableDeclarationNode): TAstValue;
-        function VisitAssignment(const Node: IAssignmentNode): TAstValue;
-    end;
-
-    // --- AST Node Interfaces (now using TAstValue) ---
-
-    // Base interface for all AST nodes.
-    IAstNode = interface(IInterface)
-        function Accept(const Visitor: IAstVisitor): TAstValue;
-    end;
-
-    // Abstract interface for all nodes that evaluate to a value.
-    IExpressionNode = interface(IAstNode)
-    end;
-
-    IConstantNode = interface(IExpressionNode)
-        {$region 'private'}
-        function GetValue: TScalar;
-        {$endregion}
-        property Value: TScalar read GetValue;
-    end;
-
-    IIdentifierNode = interface(IExpressionNode)
-        {$region 'private'}
-        function GetName: string;
-        {$endregion}
-        property Name: string read GetName;
-    end;
-
-    IBinaryExpressionNode = interface(IExpressionNode)
-        {$region 'private'}
-        function GetLeft: IExpressionNode;
-        function GetOperator: TBinaryOperator;
-        function GetRight: IExpressionNode;
-        {$endregion}
-        property Left: IExpressionNode read GetLeft;
-        property Operator: TBinaryOperator read GetOperator;
-        property Right: IExpressionNode read GetRight;
-    end;
-
-    IUnaryExpressionNode = interface(IExpressionNode)
-        {$region 'private'}
-        function GetOperator: TUnaryOperator;
-        function GetRight: IExpressionNode;
-        {$endregion}
-        property Operator: TUnaryOperator read GetOperator;
-        property Right: IExpressionNode read GetRight;
-    end;
-
-    IIfExpressionNode = interface(IExpressionNode)
-        {$region 'private'}
-        function GetCondition: IExpressionNode;
-        function GetThenBranch: IExpressionNode;
-        function GetElseBranch: IExpressionNode;
-        {$endregion}
-        property Condition: IExpressionNode read GetCondition;
-        property ThenBranch: IExpressionNode read GetThenBranch;
-        property ElseBranch: IExpressionNode read GetElseBranch;
-    end;
-
-    ILambdaExpressionNode = interface(IExpressionNode)
-        {$region 'private'}
-        function GetParameters: TArray<IIdentifierNode>;
-        function GetBody: IExpressionNode;
-        {$endregion}
-        property Parameters: TArray<IIdentifierNode> read GetParameters;
-        property Body: IExpressionNode read GetBody;
-    end;
-
-    IFunctionCallNode = interface(IExpressionNode)
-        {$region 'private'}
-        function GetCallee: IExpressionNode;
-        function GetArguments: TList<IExpressionNode>;
-        {$endregion}
-        property Callee: IExpressionNode read GetCallee;
-        property Arguments: TList<IExpressionNode> read GetArguments;
-    end;
-
-    // A block is an expression that returns the value of its last expression.
-    IBlockExpressionNode = interface(IExpressionNode)
-        {$region 'private'}
-        function GetExpressions: TList<IExpressionNode>;
-        {$endregion}
-        property Expressions: TList<IExpressionNode> read GetExpressions;
-    end;
-
-    // A variable declaration is an expression that returns an undefined value.
-    IVariableDeclarationNode = interface(IExpressionNode)
-        {$region 'private'}
-        function GetIdentifier: IIdentifierNode;
-        function GetInitializer: IExpressionNode; // Can be nil
-        {$endregion}
-        property Identifier: IIdentifierNode read GetIdentifier;
-        property Initializer: IExpressionNode read GetInitializer;
-    end;
-
-    // An assignment expression that returns the assigned value.
-    IAssignmentNode = interface(IExpressionNode)
-        {$region 'private'}
-        function GetIdentifier: IIdentifierNode;
-        function GetValue: IExpressionNode;
-        {$endregion}
-        property Identifier: IIdentifierNode read GetIdentifier;
-        property Value: IExpressionNode read GetValue;
-    end;
-
     // Record acting as a namespace for the factory functions.
     TAst = record
         class function Constant(AValue: TScalar): IConstantNode; static;
@@ -230,26 +29,12 @@ type
         class function Assign(const AIdentifier: IIdentifierNode; const AValue: IExpressionNode): IAssignmentNode; static;
     end;
 
-    // Manages the scope of execution, holding variables and their values.
-    TExecutionScope = class
-    private
-        FParent: TExecutionScope;
-        FVariables: TDictionary<string, TAstValue>;
-        procedure DumpScope(const ABuilder: TStringBuilder; AIndent: Integer);
-    public
-        constructor Create(AParent: TExecutionScope = nil);
-        destructor Destroy; override;
-        procedure Clear;
-        function FindValue(const Name: string; out Value: TAstValue): Boolean;
-        // Sets or updates a value in the current scope. Used for declarations.
-        procedure SetValue(const Name: string; const Value: TAstValue);
-        // Finds an existing variable in the scope chain and updates its value. Used for assignments.
-        procedure AssignValue(const Name: string; const Value: TAstValue);
-        function Dump: string;
-    end;
-
 implementation
 
+uses
+    System.Classes,
+    System.Generics.Collections;
+
 type
     { TAstNode }
     // Common base class for AST nodes to reduce boilerplate.
@@ -378,111 +163,6 @@ type
         function Accept(const Visitor: IAstVisitor): TAstValue; override;
     end;
 
-{ TAstValue }
-
-class operator TAstValue.Initialize(out Dest: TAstValue);
-begin
-    // Ensures the record is in a clean state when created.
-    Dest.FKind := avkUndefined;
-end;
-
-function TAstValue.AsClosure: IEvaluatorClosure;
-begin
-    if (FKind <> avkClosure) then
-        raise EInvalidCast.Create('Cannot read value as a Closure.');
-    Result := FClosure;
-end;
-
-function TAstValue.AsScalar: TScalar;
-begin
-    if (FKind <> avkScalar) then
-        raise EInvalidCast.Create('Cannot read value as a Scalar.');
-    Result := FScalar;
-end;
-
-class function TAstValue.FromClosure(const AValue: IEvaluatorClosure): TAstValue;
-begin
-    Result.FKind := avkClosure;
-    Result.FClosure := AValue;
-    Result.FScalar := Default(TScalar);
-end;
-
-class function TAstValue.FromScalar(const AValue: TScalar): TAstValue;
-begin
-    Result.FKind := avkScalar;
-    Result.FScalar := AValue;
-    Result.FClosure := nil;
-end;
-
-function TAstValue.GetIsClosure: Boolean;
-begin
-    Result := FKind = avkClosure;
-end;
-
-function TAstValue.GetIsScalar: Boolean;
-begin
-    Result := FKind = avkScalar;
-end;
-
-function TAstValue.GetIsUndefined: Boolean;
-begin
-    Result := FKind = avkUndefined;
-end;
-
-function TAstValue.GetKind: TAstValueKind;
-begin
-    Result := FKind;
-end;
-
-function TAstValue.ToString: String;
-begin
-    case FKind of
-        avkScalar: Result := FScalar.ToString;
-        avkClosure: Result := '<closure>';
-        avkUndefined: Result := '<void>';
-    else
-        Result := '[Unknown AstValue]';
-    end;
-end;
-
-class function TAstValue.Undefined: TAstValue;
-begin
-    // Returns a default-initialized record, which is avkUndefined.
-    Result := Default(TAstValue);
-end;
-
-{ TBinaryOperatorHelper }
-
-function TBinaryOperatorHelper.ToString: string;
-begin
-    case Self of
-        boAdd: Result := '+';
-        boSubtract: Result := '-';
-        boMultiply: Result := '*';
-        boDivide: Result := '/';
-        boEqual: Result := '==';
-        boNotEqual: Result := '!=';
-        boLess: Result := '<';
-        boGreater: Result := '>';
-        boLessOrEqual: Result := '<=';
-        boGreaterOrEqual: Result := '>=';
-    else
-        Result := '?';
-    end;
-end;
-
-{ TUnaryOperatorHelper }
-
-function TUnaryOperatorHelper.ToString: string;
-begin
-    case Self of
-        uoNegate: Result := '-';
-        uoNot: Result := 'not';
-    else
-        Result := '?';
-    end;
-end;
-
 { TConstantNode }
 
 constructor TConstantNode.Create(AValue: TScalar);
@@ -789,87 +469,4 @@ begin
     Result := TVariableDeclarationNode.Create(AIdentifier, AInitializer);
 end;
 
-{ TExecutionScope }
-
-constructor TExecutionScope.Create(AParent: TExecutionScope);
-begin
-    inherited Create;
-    FParent := AParent;
-    FVariables := TDictionary<string, TAstValue>.Create;
-end;
-
-destructor TExecutionScope.Destroy;
-begin
-    FVariables.Free;
-    inherited Destroy;
-end;
-
-procedure TExecutionScope.AssignValue(const Name: string; const Value: TAstValue);
-begin
-    if FVariables.ContainsKey(Name) then
-        FVariables.AddOrSetValue(Name, Value)
-    else if Assigned(FParent) then
-        FParent.AssignValue(Name, Value)
-    else
-        raise Exception.CreateFmt('Cannot assign to undeclared variable "%s".', [Name]);
-end;
-
-procedure TExecutionScope.Clear;
-begin
-    FVariables.Clear;
-    if Assigned(FParent) then
-        FParent.Clear;
-end;
-
-procedure TExecutionScope.DumpScope(const ABuilder: TStringBuilder; AIndent: Integer);
-var
-    pair: TPair<string, TAstValue>;
-    indentStr: string;
-begin
-    indentStr := ''.PadLeft(AIndent);
-    if (FVariables.Count > 0) then
-    begin
-        for pair in FVariables do
-            ABuilder.AppendLine(indentStr + Format('  %s: %s', [pair.Key, pair.Value.ToString]));
-    end
-    else
-    begin
-        ABuilder.AppendLine(indentStr + '  (empty)');
-    end;
-
-    if Assigned(FParent) then
-    begin
-        ABuilder.AppendLine(indentStr + '[Parent Scope]');
-        FParent.DumpScope(ABuilder, AIndent + 2);
-    end;
-end;
-
-function TExecutionScope.Dump: string;
-var
-    builder: TStringBuilder;
-begin
-    builder := TStringBuilder.Create;
-    try
-        builder.AppendLine('[Current Scope]');
-        DumpScope(builder, 0);
-        Result := builder.ToString.TrimRight;
-    finally
-        builder.Free;
-    end;
-end;
-
-function TExecutionScope.FindValue(const Name: string; out Value: TAstValue): Boolean;
-begin
-    Result := FVariables.TryGetValue(Name, Value);
-    if not Result and Assigned(FParent) then
-    begin
-        Result := FParent.FindValue(Name, Value);
-    end;
-end;
-
-procedure TExecutionScope.SetValue(const Name: string; const Value: TAstValue);
-begin
-    FVariables.AddOrSetValue(Name, Value);
-end;
-
 end.