网页or “syzygies”. Given a finitely generated R-module M (where R is a commutative ring) and a set z1,...,zn of generators, a syzygyof M is an element (a1,...,an) ∈ Rn for which a1z1 +···+anzn =0. The set of all syzygies (relative to the given gen-erating set) is a submodule of Rn, called the mod-ule of syzygies. Thus the module of ...