**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. |