proposition: Lemma variations_variation a b f s : itv_partition a b s -> variations a b f (variation a b f s).
proof: Proof. by move=> abs; exists s. 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)