This package develops new data types and routines for homological algebra. Eventually, it will replace the current facilities for homological algebra. We are making this available in order to get feedback from users before making this change. Please email the authors with any and all comments or suggestions.
The major change is replacing the ChainComplex data type with Complex. The internal structure of this new data type is somewhat different, but more importantly, it has a richer set of constructors. Use the functions complex(ChainComplex), complex(ChainComplexMap), chainComplex(Complex), chainComplex(ComplexMap), to translate between these representations.
The overarching goal is to make all of the homological algebra routines functorial. For instance, we have canonical maps associated to kernels, cokernels, images, coimages, cones, and cylinders.
This documentation describes version 0.9999 of Complexes.
The source code from which this documentation is derived is in the file Complexes.m2. The auxiliary files accompanying it are in the directory Complexes/.