Pascal Example of Class inheritance

  { TAddMachine }

  TAddMachine = class
    private
    public
      number1, number2, result : integer;
      constructor Create;
      destructor Destroy;
      function Add: integer;
  end;

  { TDivideMachine }

  TDivideMachine = class(TAddMachine)
    public
      function Divide: integer;
  end;

//...
implementation
//...

{ TAddMachine }

constructor TAddMachine.Create;
begin

end;

destructor TAddMachine.Destroy;
begin

end;

function TAddMachine.Add: integer;
begin
result:=number1+number2;
end;

{ TDivideMachine }

function TDivideMachine.Divide: integer;
begin
  result:=number1 div number2;
end;