- sum(ChainComplex) -- direct sum of the components of a chain complex
- sum(ChainComplexMap) -- direct sum of the components of a chain map
- sum(List) -- sum the elements of a list
- sum(Set) -- sum of elements
- sum(VirtualTally) -- sum of elements
- sum(VisibleList,Function) -- sum results of applying a function
- sum(VisibleList,VisibleList,Function) -- sum results of applying a function pairwise
- sum(ZZ,Function) -- sum consecutive values of a function

The object sum is a method function.