fact: Definition unitPCMMixin := PCMMixin UnitPCM.ujoinC UnitPCM.ujoinA UnitPCM.uunitL UnitPCM.uvalidL UnitPCM.uvalidU.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq bigop fintype finset) pcm(options axioms prelude seqperm pred seqext)