anchor.diff:  
     TExprFunctionCollector = class(TInterfacedObject, IExprFunctionCollector, IExprNodeVisitor)
     private
  -    FFunctions: IDictionary<string, Expr.NaryFunc>;
  +    FFunctions: IList<Expr.NaryFunc>;
  +    FKnownFunctions: IDictionary<string, integer>;
     public
       constructor Create;
       destructor Destroy; override;
  
positive.code: 
  function TExprFunctionCollector.GetFunctions: TArray<Expr.NaryFunc>;
  begin
    result := FFunctions.Values;
  end;
  
  procedure TExprFunctionCollector.Visit(const Node: IUnaryOpNode);
  
negative.code:     begin
        if i > 1 then
          s := s + ', ';
        s := s + DataType + ' arg_' + IntToStr(i);
      end;
      s := s + ')';
      lines.Add(s);
  