-#T1 #T2 #H elim H -T1 -T2 [||| * ]
-[ #s1 #s2 #f #X #H >(lifts_inv_sort1 … H) -H
- /3 width=3 by lifts_sort, teqx_sort, ex2_intro/
-| #i #f #X #H elim (lifts_inv_lref1 … H) -H
- /3 width=3 by lifts_lref, teqx_lref, ex2_intro/
-| #l #f #X #H >(lifts_inv_gref1 … H) -H
- /2 width=3 by lifts_gref, teqx_gref, ex2_intro/
-| #p #I #V1 #V2 #T1 #T2 #_ #_ #IHV #IHT #f #X #H elim (lifts_inv_bind1 … H) -H
- #W1 #U1 #HVW1 #HTU1 #H destruct
- elim (IHV … HVW1) -V1 elim (IHT … HTU1) -T1
- /3 width=5 by lifts_bind, teqx_pair, ex2_intro/
-| #I #V1 #V2 #T1 #T2 #_ #_ #IHV #IHT #f #X #H elim (lifts_inv_flat1 … H) -H
- #W1 #U1 #HVW1 #HTU1 #H destruct
- elim (IHV … HVW1) -V1 elim (IHT … HTU1) -T1
- /3 width=5 by lifts_flat, teqx_pair, ex2_intro/
-]
-qed-.