fact: Parameter well_formed_init_pb : forall t1 t2, well_formed_cf t1 -> well_formed_cf t2 -> well_formed_pb (init_pb t1 t2).
imports: Coq(Arith List Wellfounded Wf_nat) CoLoR(more_list list_permut list_sort term_spec term_o equational_theory ac matching dickson matching_well_formed matching_well_founded matching_sound matching_complete dickson)