 In this system, introduced as a system of conditional negation, CN, (A → ~B) and ~(A → B) have the same value under every assignment of truth values to propositional variables. Cantwell’s system thus validates BTe and BTe′, and it turns out to be the connexive logic MC from Wansing 2005, see section 4.5.3, extended by the Law of Excluded Middle, A ∨ ~A. A certain expansion of CN is studied in Olkhovikov 2002, 2016 and, independently, in Omori 2016c, see section 4.5.3.