proposition: Lemma opp_lfunE f x : (- f) x = - f x.
proof: Proof. exact: lfunE. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop finfun tuple) mathcomp(ssralg matrix mxalgebra zmodp)