proposition: Lemma limf_esupE f F : limf_esup f F = ereal_inf [set ereal_sup (f @` V) | V in F].
proof: Proof. by []. 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