proposition: Lemma segment_continuous_surjective a b f : a <= b -> {within `[a, b], continuous f} -> set_surj `[a, b] (f @`[a, b]) f.
proof: Proof. by move=> ? fct y/= /IVT[]// x; exists x. Qed.
imports: mathcomp(all_ssreflect ssralg ssrint ssrnum finmap) mathcomp(matrix interval zmodp vector fieldext falgebra) mathcomp(mathcomp_extra boolp classical_sets functions) mathcomp(cardinality) ereal reals signed topology prodnormedzmodule normedtype derive sequences real_interval HB(structures)