#g #Hg #H destruct /3 width=3 by drops_inv_drop1/
| #f1 #I #K1 #K #V1 #V #_ #HV1 #IH #b2 #f #L2 #HL2 #f2 #Hf elim (after_inv_pxx … Hf) -Hf [1,3: * |*:// ]
#g2 #g #Hf #H1 #H2 destruct
#g #Hg #H destruct /3 width=3 by drops_inv_drop1/
| #f1 #I #K1 #K #V1 #V #_ #HV1 #IH #b2 #f #L2 #HL2 #f2 #Hf elim (after_inv_pxx … Hf) -Hf [1,3: * |*:// ]
#g2 #g #Hf #H1 #H2 destruct