NAME
    pmodm127 - calculate q mod 2^(2^127-1)

SYNOPSIS
    custom("pmodm127", q)

TYPES
    q           int > 0

    return      int

DESCRIPTION

    This custom function will return the value:

        q mod 2^(2^127-1)

    This custom function serves as a demonstration of how to write
    a custom function.  It performs the equivalent of:

        pmod(2, 2^127-1, q)

    The return value is integer in the half open range: [0, q).

    SPECIAL NOTE:

        Can you find a value, q, for which this custom function returns 1?
        If you do, send the value of q to chongo using the Email address
        found at:

            http://www.isthe.com/chongo/address.html

EXAMPLE
    > custom("pmodm127", 65537)
            32769

    > custom("pmodm127", 2^31-1)
            8

    > custom("pmodm127", 7^51+2)
            11228202966269457258557496419097462731193173

LIMITS
    calc must be built with ALLOW_CUSTOM= -DCUSTOM
    calc must be executed with a -C arg.
    q must be an integer > 0

LIBRARY
    none

SEE ALSO
    custom

## Copyright (C) 2004,2021  Landon Curt Noll
##
## Calc is open software; you can redistribute it and/or modify it under
## the terms of the version 2.1 of the GNU Lesser General Public License
## as published by the Free Software Foundation.
##
## Calc is distributed in the hope that it will be useful, but WITHOUT
## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
## or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General
## Public License for more details.
##
## A copy of version 2.1 of the GNU Lesser General Public License is
## distributed with calc under the filename COPYING-LGPL.  You should have
## received a copy with calc; if not, write to Free Software Foundation, Inc.
## 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
##
## Under source code control:   2004/02/25 07:13:15
## File existed as early as:    2004
##
## chongo <was here> /\oo/\     http://www.isthe.com/chongo/
## Share and enjoy!  :-)        http://www.isthe.com/chongo/tech/comp/calc/
