Appendix to "Real second-order freeness and the asymptotic real   second-order freeness of several real matrix models": Examples and Diagrams
  We present examples and diagrams illustrating the proofs appearing in "Real second-order freeness and the asymptotic real second-order freeness of several real matrix models", to which this paper is meant to be an appendix. We show how matrix calculations may be represented by topological surface gluings, which may in turn be represented as permutations. 
C. Emily I. Redelmeier
math.PR math.CO math.FA math.OA