Freeness theorems for operads via Gr\"obner bases.

link: http://arxiv.org/abs/0907.4958
Abstract

We show how to use Groebner bases for operads to prove various freeness
theorems: freeness of certain operads as nonsymmetric operads, freeness of an
operad Q as a P-module for an inclusion P into Q, freeness of a suboperad. This
gives new proofs of many known results of this type and helps to prove some new
results.