NAME
    minv - inverse of an integer modulo a specified integer

SYNOPSIS
    minv(x, md)

TYPES
    x		integer
    md    	integer

    return	integer

DESCRIPTION
    If x and md are not relatively prime, zero is returned.
    Otherwise v = minv(x, md) is the canonical residue v modulo md
    for which v * x is congruent to 1 modulo md.   The canonical
    residues modulo md are determined as follows by md and bits 0, 2
    and 4 of config("mod") (other bits are ignored).

		config("mod")	  md > 0	      md < 0

		    0		0 < v < md	   md < v < 0
		    1	      -md < v < 0	    0 < v < -md
		    4		0 < v < md	    0 < v < -md
		    5         -md < v < 0	   md < v < 0
		   16	    -md/2 < v <= md/2   md/2 <= v < -md/2
		   17      -md/2 <= v < md/2     md/2 < v <= -md/2
		   20	    -md/2 < v <= md/2    md/2 < v <= -md/2
		   21	   -md/2 <= v < md/2    md/2 <= v < -md/2

EXAMPLE
    > c = config("mod", 0)
    > print minv(3,10), minv(-3,10), minv(3,-10), minv(-3,-10), minv(4,10)
    7 3 -3 -7 0

    > c = config("mod",16)
    > print minv(3,10), minv(-3,10), minv(3,-10), minv(-3,-10), minv(4,10)
    -3 3 -3 3 0

LIMITS
    none

LIBRARY
    NUMBER *qminv(NUMBER *x, NUMBER *md)

SEE ALSO
    mod, pmod