fact: Definition isomorphisms (psi : 'Mor(N, M)) := (phi ** psi %= idm) && (psi ** phi %= idm).
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq path) mathcomp(ssralg fintype perm choice matrix bigop zmodp mxalgebra poly) ssrcomplements stronglydiscrete coherent edr