michael@0: # This Source Code Form is subject to the terms of the Mozilla Public
michael@0: # License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0: # file, You can obtain one at http://mozilla.org/MPL/2.0/.
michael@0: 
michael@0: =head1 NAME
michael@0: 
michael@0:  invmod - compute modular inverse of an integer
michael@0: 
michael@0: =head1 SYNOPSIS
michael@0: 
michael@0:  invmod <a> <m>
michael@0: 
michael@0: =head1 DESCRIPTION
michael@0: 
michael@0: The B<invmod> program computes the inverse of I<a>, modulo I<m>, if
michael@0: that inverse exists.  Both I<a> and I<m> are arbitrary-precision
michael@0: integers in decimal notation.  The result is written in standard
michael@0: decimal notation to the standard output.
michael@0: 
michael@0: If there is no inverse, the message:
michael@0: 
michael@0:  No inverse
michael@0: 
michael@0: ...will be printed to the standard output (an inverse exists if and
michael@0: only if the greatest common divisor of I<a> and I<m> is 1).
michael@0: 
michael@0: =head1 SEE ALSO
michael@0: 
michael@0: gcd(1), isprime(1), lap(1)
michael@0: 
michael@0: =head1 AUTHOR
michael@0: 
michael@0:  Michael J. Fromberger <sting@linguist.dartmouth.edu>
michael@0:  Thayer School of Engineering, Hanover, New Hampshire, USA