fact: Parameter flatten_build_inside : forall f t l1 l2, arity f = AC -> well_formed_cf (Term f (l1 ++ t :: l2)) -> permut (flatten f ((build f (l1 ++ l2)) :: nil)) (l1 ++ l2).
imports: Coq(Relations List Arith Morphisms) CoLoR(more_list list_permut list_sort term_spec term_o equational_theory_spec equational_theory)