Stanley, R.P. Order (1984) 1: 29. doi:10.1007/BF00396271
An elementary, self-contained proof of a result of Pouzet and Rosenberg and of Harper is given. This result states that the quotient of certain posets (called unitary Peck) by a finite group of automorphisms retains some nice properties, including the Sperner property. Examples of unitary Peck posets are given, and the techniques developed here are used to prove a result of Lovász on the edge-reconstruction conjecture.
AMS (MOS) subject classifications (1980)
Primary 06A10 secondary 05C60 20B25
Poset Peck poset Sperner property automorphism group quotient poset edge-reconstruction