public bool operator !=( 
   MouseButtonCombination mbc1,
   MouseButtonCombination mbc2
)

class Program
{
   private MouseButtonCombination mbc1;
   private MouseButtonCombination mbc2;
            
   public MouseButtonCombination MouseCombination1
   {set{mbc1 = value};} 
   public MouseButtonCombination MouseCombination2
   {set{mbc2 = value;}}
            
   public bool CheckEquality()
   {
      if(mbc1 != mbc2)
         return false;
      else
         return true; 
   }
}