ResolutionCubicalCrustGroup(G,k):: MatrixGroup, Int --> FreeResolution

Inputs a crystallographic group G represented using AffineCrystGroupOnRight as in the GAP package Cryst together with an integer k \ge 1. The function tries to find a cubical fundamental domain in the Euclidean space \mathbb R^n on which G acts. If it succeeds it uses this domain to return k+1 terms of a free ZG-resolution of \mathbb Z.

This function was written by Bui Anh Tuan.