Functions for the rational mode
| INTSQR(x) | the value of the positive square root of x truncated to an integer. |
| NUMER(x) | The numerator of x. |
| DENOM(x) | The denominator of x. |
| GCD(x,y) | The Greatest Common Divisor of x and y. Results have positive signs. If both x and y are equal to zero, the exception with extype 3006 shall be raised. |