fact: CoInductive T2leq_xor_gtn m n : bool -> bool -> Set := | T2GeqNotGtn of m <= n : T2leq_xor_gtn m n true false | T2GtnNotLeq of n < m : T2leq_xor_gtn m n false true.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(fintype bigop)