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# isDirectSum -- whether something is a direct sum

## Description

Works for modules, chain complexes, etc. The components of the sum can be recovered with components.

    i1 : isDirectSum ZZ^6

    o1 = false

    i2 : F = ZZ^2 ++ ZZ^3

           5
    o2 = ZZ

    o2 : ZZ-module, free

    i3 : isDirectSum F

    o3 = true

    i4 : components F

            2    3
    o4 = {ZZ , ZZ }

    o4 : List

## Ways to use isDirectSum:

- `isDirectSum(Module)`

## For the programmer

The object isDirectSum is a method function.

The source of this document is in /build/macaulay2-88fgJW/macaulay2-1.25.11+ds/M2/Macaulay2/packages/Macaulay2Doc/functions/directSum-doc.m2:26:0.