(* activate genv *)
(* extended reducible terms *)
inductive crx (h) (g) (G:genv): relation2 lenv term ≝
-| crx_sort : ∀L,k,l. deg h g k (l+1) → crx h g G L (⋆k)
+| crx_sort : ∀L,k,d. deg h g k (d+1) → crx h g G L (⋆k)
| crx_delta : ∀I,L,K,V,i. ⬇[i] L ≡ K.ⓑ{I}V → crx h g G L (#i)
| crx_appl_sn: ∀L,V,T. crx h g G L V → crx h g G L (ⓐV.T)
| crx_appl_dx: ∀L,V,T. crx h g G L T → crx h g G L (ⓐV.T)
(* Basic inversion lemmas ***************************************************)
fact crx_inv_sort_aux: ∀h,g,G,L,T,k. ⦃G, L⦄ ⊢ ➡[h, g] 𝐑⦃T⦄ → T = ⋆k →
- ∃l. deg h g k (l+1).
+ ∃d. deg h g k (d+1).
#h #g #G #L #T #k0 * -L -T
-[ #L #k #l #Hkl #H destruct /2 width=2 by ex_intro/
+[ #L #k #d #Hkd #H destruct /2 width=2 by ex_intro/
| #I #L #K #V #i #HLK #H destruct
| #L #V #T #_ #H destruct
| #L #V #T #_ #H destruct
]
qed-.
-lemma crx_inv_sort: ∀h,g,G,L,k. ⦃G, L⦄ ⊢ ➡[h, g] 𝐑⦃⋆k⦄ → ∃l. deg h g k (l+1).
+lemma crx_inv_sort: ∀h,g,G,L,k. ⦃G, L⦄ ⊢ ➡[h, g] 𝐑⦃⋆k⦄ → ∃d. deg h g k (d+1).
/2 width=5 by crx_inv_sort_aux/ qed-.
fact crx_inv_lref_aux: ∀h,g,G,L,T,i. ⦃G, L⦄ ⊢ ➡[h, g] 𝐑⦃T⦄ → T = #i →
∃∃I,K,V. ⬇[i] L ≡ K.ⓑ{I}V.
#h #g #G #L #T #j * -L -T
-[ #L #k #l #_ #H destruct
+[ #L #k #d #_ #H destruct
| #I #L #K #V #i #HLK #H destruct /2 width=4 by ex1_3_intro/
| #L #V #T #_ #H destruct
| #L #V #T #_ #H destruct
fact crx_inv_gref_aux: ∀h,g,G,L,T,p. ⦃G, L⦄ ⊢ ➡[h, g] 𝐑⦃T⦄ → T = §p → ⊥.
#h #g #G #L #T #q * -L -T
-[ #L #k #l #_ #H destruct
+[ #L #k #d #_ #H destruct
| #I #L #K #V #i #HLK #H destruct
| #L #V #T #_ #H destruct
| #L #V #T #_ #H destruct
/2 width=8 by crx_inv_gref_aux/ qed-.
lemma trx_inv_atom: ∀h,g,I,G. ⦃G, ⋆⦄ ⊢ ➡[h, g] 𝐑⦃⓪{I}⦄ →
- ∃∃k,l. deg h g k (l+1) & I = Sort k.
+ ∃∃k,d. deg h g k (d+1) & I = Sort k.
#h #g * #i #G #H
[ elim (crx_inv_sort … H) -H /2 width=4 by ex2_2_intro/
| elim (crx_inv_lref … H) -H #I #L #V #H
fact crx_inv_ib2_aux: ∀h,g,a,I,G,L,W,U,T. ib2 a I → ⦃G, L⦄ ⊢ ➡[h, g] 𝐑⦃T⦄ →
T = ⓑ{a,I}W.U → ⦃G, L⦄ ⊢ ➡[h, g] 𝐑⦃W⦄ ∨ ⦃G, L.ⓑ{I}W⦄ ⊢ ➡[h, g] 𝐑⦃U⦄.
#h #g #b #J #G #L #W0 #U #T #HI * -L -T
-[ #L #k #l #_ #H destruct
+[ #L #k #d #_ #H destruct
| #I #L #K #V #i #_ #H destruct
| #L #V #T #_ #H destruct
| #L #V #T #_ #H destruct
fact crx_inv_appl_aux: ∀h,g,G,L,W,U,T. ⦃G, L⦄ ⊢ ➡[h, g] 𝐑⦃T⦄ → T = ⓐW.U →
∨∨ ⦃G, L⦄ ⊢ ➡[h, g] 𝐑⦃W⦄ | ⦃G, L⦄ ⊢ ➡[h, g] 𝐑⦃U⦄ | (𝐒⦃U⦄ → ⊥).
#h #g #G #L #W0 #U #T * -L -T
-[ #L #k #l #_ #H destruct
+[ #L #k #d #_ #H destruct
| #I #L #K #V #i #_ #H destruct
| #L #V #T #HV #H destruct /2 width=1 by or3_intro0/
| #L #V #T #HT #H destruct /2 width=1 by or3_intro1/