lemma nta_ldef (h) (a) (G) (K):
∀V,W. ⦃G,K⦄ ⊢ V :[h,a] W →
- â\88\80U. â¬\86*[1] W ≘ U → ⦃G,K.ⓓV⦄ ⊢ #0 :[h,a] U.
+ â\88\80U. â\87§*[1] W ≘ U → ⦃G,K.ⓓV⦄ ⊢ #0 :[h,a] U.
#h #a #G #K #V #W #H #U #HWU
elim (cnv_inv_cast … H) -H #X #HW #HV #HWX #HVX
lapply (cnv_lifts … HW (Ⓣ) … (K.ⓓV) … HWU) -HW
lemma nta_ldec_cnv (h) (a) (G) (K):
∀W. ⦃G,K⦄ ⊢ W ![h,a] →
- â\88\80U. â¬\86*[1] W ≘ U → ⦃G,K.ⓛW⦄ ⊢ #0 :[h,a] U.
+ â\88\80U. â\87§*[1] W ≘ U → ⦃G,K.ⓛW⦄ ⊢ #0 :[h,a] U.
#h #a #G #K #W #HW #U #HWU
lapply (cnv_lifts … HW (Ⓣ) … (K.ⓛW) … HWU)
/3 width=5 by cnv_zero, cnv_cast, cpms_ell, drops_refl, drops_drop/
lemma nta_lref (h) (a) (I) (G) (K):
∀T,i. ⦃G,K⦄ ⊢ #i :[h,a] T →
- â\88\80U. â¬\86*[1] T ≘ U → ⦃G,K.ⓘ{I}⦄ ⊢ #(↑i) :[h,a] U.
+ â\88\80U. â\87§*[1] T ≘ U → ⦃G,K.ⓘ{I}⦄ ⊢ #(↑i) :[h,a] U.
#h #a #I #G #K #T #i #H #U #HTU
elim (cnv_inv_cast … H) -H #X #HT #Hi #HTX #H2
lapply (cnv_lifts … HT (Ⓣ) … (K.ⓘ{I}) … HTU) -HT
(* Basic_2A1: was by definition: nta_ldef ntaa_ldef *)
lemma nta_ldef_drops (h) (a) (G) (K) (L) (i):
∀V,W. ⦃G,K⦄ ⊢ V :[h,a] W →
- â\88\80U. â¬\86*[â\86\91i] W â\89\98 U â\86\92 â¬\87*[i] L ≘ K.ⓓV → ⦃G,L⦄ ⊢ #i :[h,a] U.
+ â\88\80U. â\87§*[â\86\91i] W â\89\98 U â\86\92 â\87©*[i] L ≘ K.ⓓV → ⦃G,L⦄ ⊢ #i :[h,a] U.
#h #a #G #K #L #i #V #W #HVW #U #HWU #HLK
elim (lifts_split_trans … HWU (𝐔❴1❵) (𝐔❴i❵)) [| // ] #X #HWX #HXU
/3 width=9 by nta_lifts_bi, nta_ldef/
lemma nta_ldec_drops_cnv (h) (a) (G) (K) (L) (i):
∀W. ⦃G,K⦄ ⊢ W ![h,a] →
- â\88\80U. â¬\86*[â\86\91i] W â\89\98 U â\86\92 â¬\87*[i] L ≘ K.ⓛW → ⦃G,L⦄ ⊢ #i :[h,a] U.
+ â\88\80U. â\87§*[â\86\91i] W â\89\98 U â\86\92 â\87©*[i] L ≘ K.ⓛW → ⦃G,L⦄ ⊢ #i :[h,a] U.
#h #a #G #K #L #i #W #HW #U #HWU #HLK
elim (lifts_split_trans … HWU (𝐔❴1❵) (𝐔❴i❵)) [| // ] #X #HWX #HXU
/3 width=9 by nta_lifts_bi, nta_ldec_cnv/