fact: Parameter well_formed_cf_apply_subst : forall sigma, well_formed_cf_subst sigma -> forall t, well_formed_cf t -> well_formed_cf (apply_cf_subst sigma t).
imports: Coq(Relations List Arith Morphisms) CoLoR(more_list list_permut list_sort term_spec term_o equational_theory_spec equational_theory)