FreeGResolution(P,n):: NonFreeResolution, Int --> FreeResolution

Inputs a non-free $\mathbb ZG$-resolution $P_\ast$ and a positive integer n. It attempts to return n terms of a free \mathbb ZG-resolution of \mathbb Z. However, the stabilizer groups in the non-free resolution must be such that HAP can construct free resolutions with contracting homotopies for them.

The contracting homotopy on the resolution was implemented by Bui Anh Tuan.