Listing 2: The COMCalc interfaces

//iclient.h

interface IAddSub : IUnknown
{
  virtual int pascal Add(int x, int y)=0;
  virtual int pascal Subtract(int x, int y)=0;
};

interface IMulDiv : IUnknown
{
  virtual int pascal Multiply(int x, int y)=0;
  virtual int pascal Divide(int x, int y)=0;
};

interface ITrigonometry : IUnknown
{
  
};
//End of File