#h #G #L #T1 #T2 #H @(cprs_ind_sn … H) -T2
/3 width=3 by cpcs_cpr_div, cpcs_step_sn, cpcs_cprs_dx/
qed.
(* Basic_2A1: was: cpcs_cprs_strap1 *)
lemma cpcs_cprs_step_dx (h) (G) (L): ∀T1,T. ❪G,L❫ ⊢ T1 ⬌*[h] T →
#h #G #L #T1 #T2 #H @(cprs_ind_sn … H) -T2
/3 width=3 by cpcs_cpr_div, cpcs_step_sn, cpcs_cprs_dx/
qed.
(* Basic_2A1: was: cpcs_cprs_strap1 *)
lemma cpcs_cprs_step_dx (h) (G) (L): ∀T1,T. ❪G,L❫ ⊢ T1 ⬌*[h] T →