Norm1ToriHNP for GAP 4 See the URL below for further explanations. https://www.math.kyoto-u.ac.jp/~yamasaki/Algorithm/Norm1ToriHNP/FlabbyResolutionFromBase.html https://www.math.kyoto-u.ac.jp/~yamasaki/Algorithm/Norm1ToriHNP/HNP.html