fact: Variable Urysohns_lemma_function: forall F G:Ensemble X, closed F -> closed G -> Intersection F G = Empty_set -> { f:X -> RTop | continuous f /\ (forall x:X, 0 <= f x <= 1) /\ (forall x:X, In F x -> f x = 0) /\ (forall x:X, In G x -> f x = 1) }.
imports: RTopology SeparatednessAxioms RFuncContinuity UniformTopology ContinuousFactorization Coq(Description Max Psatz ClassicalChoice) ZornsLemma(Proj1SigInjective) UrysohnsLemma