fact: Definition mxE := ((((mxE1, mxE2), (mxE3)), ((mxE5, mx_injE), (mx_valid))), (((unitL, unitR), (valid_unit, eq_refl)), ((valid_undef, undef_join), join_undef))).
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq) pcm(options prelude pred) pcm(pcm morphism natmap)