public static Bool Visit(Bool op1, EqualToOp op, Bool op2)
 {
     return(new Bool(op1.data == op2.data));
 }
 public static Bool Visit(Double op1, EqualToOp op, Integer op2)
 {
     return(new Bool((int)(op1.data) == op2.data));
 }
 public static Bool Visit(Integer op1, EqualToOp op, Double op2)
 {
     return(new Bool(op1.data == ((int)op2.data)));
 }
 // EqualTo
 public static Bool Visit(Integer op1, EqualToOp op, Integer op2)
 {
     return(new Bool(op1.data == op2.data));
 }