proposition: Lemma cvgrVNy f : (\near a, 0 > f a) -> f\^-1 @ a --> -oo <-> f @ a --> 0.
proof: Proof. by move=> f_lt0; rewrite -ltr0_cvgV0 ?inv_funK//; near do rewrite invr_lt0. 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