⦃G1, L1, T1⦄ ⊐+ ⦃G2, L2, T2⦄.
/2 width=5 by tri_TC_strap/ qed.
-lemma fqup_drop: ∀G1,G2,L1,K1,K2,T1,T2,U1,e. ⬇[e] L1 ≡ K1 → ⬆[0, e] T1 ≡ U1 →
+lemma fqup_drop: ∀G1,G2,L1,K1,K2,T1,T2,U1,m. ⬇[m] L1 ≡ K1 → ⬆[0, m] T1 ≡ U1 →
⦃G1, K1, T1⦄ ⊐+ ⦃G2, K2, T2⦄ → ⦃G1, L1, U1⦄ ⊐+ ⦃G2, K2, T2⦄.
-#G1 #G2 #L1 #K1 #K2 #T1 #T2 #U1 #e #HLK1 #HTU1 #HT12 elim (eq_or_gt … e) #H destruct
+#G1 #G2 #L1 #K1 #K2 #T1 #T2 #U1 #m #HLK1 #HTU1 #HT12 elim (eq_or_gt … m) #H destruct
[ >(drop_inv_O2 … HLK1) -L1 <(lift_inv_O2 … HTU1) -U1 //
| /3 width=5 by fqup_strap2, fqu_drop_lt/
]