| #K0 #l1 #l2 * [ #l01 ] #H1 * [1,3: #l02 ] #H2 //
[ < H2 in H1; -H2 #H
lapply (nexts_inj … H) -H #H destruct //
- | elim (H1 ?) /2 width=2/
- | elim (H2 ?) /2 width=2/
+ | elim H1 /2 width=2/
+ | elim H2 /2 width=2/
]
| #k0 #l0 *
[ #l #H destruct elim l -l normalize /2 width=1/