case NOT:
expressions[index] = new NotCheck(exp);
break;
case MUL:
expressions[index] = mode == INTEGER ? new MulInteger(exp,
expressions[index + 1]) : new MulDouble(exp, expressions[index + 1]);
break;
case DIV:
expressions[index] = mode == INTEGER ? new DivInteger(exp,
expressions[index + 1]) : new DivDouble(exp, expressions[index + 1]);
break;