proposition: Lemma Urysohn_continuous (A B : set T) : continuous (Urysohn A B).
proof: Proof. by have [] := projT2 (cid (@Urysohn' A B)). 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