diff --git a/CHANGELOG_UNRELEASED.md b/CHANGELOG_UNRELEASED.md index f938fac2e..b81edda14 100644 --- a/CHANGELOG_UNRELEASED.md +++ b/CHANGELOG_UNRELEASED.md @@ -16,6 +16,9 @@ - in `realfun.v`: + lemmas `cvg_pinftyP`, `cvg_ninftyP` +- in `topology.v`: + + lemma `in_nearW` + ### Changed ### Renamed diff --git a/theories/topology.v b/theories/topology.v index 123ab26ce..4eff4ff4f 100644 --- a/theories/topology.v +++ b/theories/topology.v @@ -7176,3 +7176,13 @@ Qed. Local Close Scope relation_scope. #[global] Hint Resolve uniform_regular : core. + +Lemma in_nearW (R : topologicalType) (P : R -> Prop) (S : set R) : + @open R^o S -> + {in S, forall x, P x} -> + {in S, forall x, \near x, P x}. +Proof. +move=> oS HP z /set_mem Sz. +rewrite -nbhs_nearE nbhsE/=. +by exists S; last move=> x /mem_set/HP. +Qed.