Subject: bar construction signs Date: Sat, 02 Mar 2002 08:10:58 -0500 From: jim stasheff Related to the bidegree issue here recently, there are (at least) two sets of signs in common use. These have very nice topological coresspondence: BG can be realized as a quotient of the disjoint union (over n) of \Delta^n x G^n or of (I x G)^n I think one of the best introductions to the bar construction is the Seminaire H Cartan 1954-55 jim