#R #L1 #L2 #d #i #H elim (llpx_sn_alt1_inv_alt … H) -H
#HL12 #IH elim (lt_or_ge i (|L1|)) /3 width=1 by or3_intro0, conj/
elim (ylt_split i d) /3 width=1 by or3_intro1/
#R #L1 #L2 #d #i #H elim (llpx_sn_alt1_inv_alt … H) -H
#HL12 #IH elim (lt_or_ge i (|L1|)) /3 width=1 by or3_intro0, conj/
elim (ylt_split i d) /3 width=1 by or3_intro1/