proposition: Lemma opp_continuous : continuous (@GRing.opp V).
proof: Proof. move=> x; apply/cvgrPdist_lt=> e e0; near do rewrite -opprD normrN. exact: cvgr_dist_lt. Unshelve. all: by end_near. 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