NAME
    sum - sum, or sum of defined sums

SYNOPSIS
    sum(x_1, x_2, ...)

TYPES
    x_1, x_2, ...	any

    return		any

DESCRIPTION
    If an argument x_i is a list with elements e_1, e_2, ..., e_n, it
    is treated as if x_i were replaced by e_1, e_2, ..., e_n; this may
    continue recurively if any of the e_j is a list.

    If an argument x_i is an object of type xx, then x_i is replaced by
    xx_sum(x_i) if the function xx_sum() has been defined.  If the
    type xx has been defined by:

		obj xx = {x, y, z},

    an appropriate definition of xx_sum(a) is sometimes a.x + a.y + a.z.
    sum(a) then returns the sum of the elements of a.

    If x_i has the null value, it is ignored.  Thus, sum(a, , b, , c)
    will return the same as sum(a, b, c).

    Assuming the above replacements, and that the x_1, x_2, ..., are
    of types for which addition is defined, sum(x_1, x_2, ...) returns
    the sum of the arguments.

EXAMPLE
    ; print sum(2), sum(5, 3, 7, 2, 9), sum(3.2, -0.5, 8.7, -1.2, 2.5)
    2 26 12.7

    ; print sum(list(3,5), 7, list(6, list(7,8), 2))
    38


    ; obj point {x, y}
    ; define point_add(a,b) = obj point = {a.x + b.x, a.y + b.y}
    ; obj point A = {1, 5}
    ; obj point B = {1, 4}
    ; obj point C = {3, 3}
    ; print sum(A, B, C)
    obj point {5, 12}

    ; define point_sum(a) = a.x
    ; print sum(A, B, C)
    5

LIMITS
    The number of arguments is not to exceed 1024.

LINK LIBRARY

SEE ALSO
    max, min, obj, ssq

## Copyright (C) 1999-2006  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:	1997/03/10 03:59:59
## File existed as early as:	1997
##
## chongo <was here> /\oo/\	http://www.isthe.com/chongo/
## Share and enjoy!  :-)	http://www.isthe.com/chongo/tech/comp/calc/
