`inv'
-----

inv(I,M)
     :: M $B$rK!$H$9$k(B I $B$N5U?t(B

RETURN
     $B@0?t(B

I,M
     $B@0?t(B

   * IA == 1 mod (M) $B$J$k@0?t(B A $B$r5a$a$k(B.

   * I $B$H(B M $B$O8_$$$KAG$G$J$1$l$P$J$i$J$$$,(B, `inv()' $B$O(B
     $B$=$N%A%'%C%/$O9T$o$J$$(B.

     [71] igcd(1234,4321);
     1
     [72] inv(1234,4321);
     3239
     [73] irem(3239*1234,4321);
     1

$B;2>H(B
     *Note `igcd igcdcntl': igcd igcdcntl.

