proposition: Lemma normrZV (x : V) : `|x| \in GRing.unit -> `| `| x |^-1 *: x | = 1.
proof: Proof. by move=> nxu; rewrite normrZ normrV// normr_id mulVr. Qed.
imports: HB(structures) mathcomp(all_ssreflect ssralg ssrint ssrnum finmap matrix) mathcomp(rat interval zmodp vector fieldext falgebra) mathcomp(mathcomp_extra boolp classical_sets functions) mathcomp(cardinality set_interval Rstruct) ereal reals signed topology prodnormedzmodule