fact: Definition strict_from_f (fz :Z) := if injectiveP fz.1 is ReflectT h then strict_from h else fz.1.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq path) mathcomp(ssralg fintype perm choice finfun) mathcomp(matrix bigop zmodp mxalgebra fingroup) minor