Vocabulary
math

Inputs and outputs

x	an integer
y	an integer
a	an integer
d	an integer

Word description
Computes the positive greatest common divisor d of x and y, and another value a satisfying:

a*y = d mod x

Notes
If d is 1, then a is the inverse of y modulo x.

Definition

USING: kernel math.private ;

IN: math

: gcd ( x y -- a d ) [ 0 1 ] 2dip (gcd) dup 0 < [ neg ] when
; inline