# Module ++ Module -- direct sum of modules

• Operator: ++

## Description

M++N -- computes the direct sum of two modules (or coherent sheaves).
 i1 : R = ZZ/101[a..c]; i2 : image vars R ++ kernel vars R o2 = image {0} | a b c 0 0 0 | {1} | 0 0 0 -b 0 -c | {1} | 0 0 0 a -c 0 | {1} | 0 0 0 0 b a | 4 o2 : R-module, submodule of R

The projection and inclusion maps for direct sums can be obtained with the following methods.

The components can be recovered later with components or with formation.