fact: Definition strict_from (f: {ffun 'I_k -> 'I_l}) (hf: injective f) := finfun (fun x => @enum_val _ (mem (codom f)) (cast_ord (cast1 hf) x)).
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq path) mathcomp(ssralg fintype perm choice finfun) mathcomp(matrix bigop zmodp mxalgebra fingroup) minor