A Gray Code for cross-bifix-free sets
  A cross-bifix-free set of words is a set in which no prefix of any length of any word is the suffix of any other word in the set. A construction of cross-bifix-free sets has recently been proposed by Chee {\it et al.} in 2013 within a constant factor of optimality. We propose a \emph{trace partitioned} Gray code for these cross-bifix-free sets and a CAT algorithm generating it. 
Antonio Bernini, Stefano Bilotta, Renzo Pinzani, Vincent Vajnovszki
cs.IT cs.DM math.CO math.IT