# isDirectSum -- whether something is a direct sum

## Description

Works for modules, graded modules, 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(ChainComplex)"