(* Properties with sort-irrelevant whd equivalence on terms *****************)
lemma cprs_abbr_pos_twneq (h) (G) (L) (V) (T1):
- â\88\83â\88\83T2. â¦\83G,Lâ¦\84 ⊢ +ⓓV.T1 ➡*[h] T2 & (+ⓓV.T1 ≅ T2 → ⊥).
+ â\88\83â\88\83T2. â\9dªG,Lâ\9d« ⊢ +ⓓV.T1 ➡*[h] T2 & (+ⓓV.T1 ≅ T2 → ⊥).
#h #G #L #V #U1
elim (cpr_subst h G (L.ⓓV) U1 … 0) [|*: /2 width=4 by drops_refl/ ] #U2 #T2 #HU12 #HTU2
elim (tweq_dec U1 U2) [ #HpU12 | -HTU2 #HnU12 ]