proposition: Lemma eigenspace_sub_geigen n (g : 'M_n) a : (eigenspace g a <= geigenspace g a)%MS.
proof: Proof. case: n => [|n] in g *; rewrite ?thinmx0 ?sub0mx// geigenspaceE. by apply/sub_kermxP; rewrite exprS mulmxA mulmx_ker mul0mx. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(div fintype tuple finfun bigop fingroup perm) mathcomp(ssralg zmodp matrix mxalgebra poly polydiv)