ABSTRACT
This chapter discusses a Rex analogue of virtual connections, namely pairing strategies. Martin Gardner mentioned Rex in his 1957 Hex column and again in a column in 1975. To play Hex; it helps to understand virtual connections and inferior cell analyis; to play Rex; it helps to understand the Rex analogues of these notions. For a Rex position, a pre-join-pair is a set of empty cells that, when one is coloured, leaves a join-pair for that colour. In Rex as in Hex, inferior cell analysis starts with dead cells. Robert Winder proved the last property while a student at Princeton. Gardner learned of Winder’s proof — which he called ‘involved’1 in his July 1957 Hex column — during his evening conversation with John Nash. Around 1974 at the University of Wisconsin-Madison, Ronald J. Evans taught a math course based on Excursions into Mathematics by Anatole Beck, Michael N. Bleicher and Donald W. Crowe.
