a bijectionist's toolkit

[Martin R]

Dear combinatorialists,

on https://trac.sagemath.org/ticket/33238 you can now find what a group of 2 combinatorialists and 2 optimizers worked on over the last 2 years, waiting for review.

In a nutshell, if you have two finite sets A and B of the same cardinality, and a couple of constraints, such as equidistributed statistics or intertwining relations, this toolkit helps you analyze what possibilities there are for a bijection between A and B.

The same engine will also help you to find a statistic, i.e. a map from A to some set Z, which is equidistributed with another statistic on B that you know, but has extra properties you desire.

I'd be grateful for comments and, of course, a review.

Martin