elim (aaa_inv_lref_drops … H) -H #J #K1 #V1 #HLK1 #HA
elim (lifts_inv_lref1 … HX) -HX #i2 #Hf #H destruct
lapply (drops_trans … HL21 … HLK1 ??) -HL21 [1,2: // ] #H
elim (aaa_inv_lref_drops … H) -H #J #K1 #V1 #HLK1 #HA
elim (lifts_inv_lref1 … HX) -HX #i2 #Hf #H destruct
lapply (drops_trans … HL21 … HLK1 ??) -HL21 [1,2: // ] #H