-lemma lsubsv_fwd_lsuba: ∀h,g,L1,L2. h ⊢ L1 ¡⊑[g] L2 → L1 ⁝⊑ L2.
-#h #g #L1 #L2 #H elim H -L1 -L2 // /2 width=1/
-#L1 #L2 #W #V #W1 #V2 #l #HV #HW #_ #_ #_ #IHL12 -W1 -V2
-elim (snv_fwd_aaa … HV) -HV #A #HV
+lemma lsubsv_fwd_lsuba: ∀h,g,G,L1,L2. G ⊢ L1 ⫃¡[h, g] L2 → G ⊢ L1 ⫃⁝ L2.
+#h #g #G #L1 #L2 #H elim H -L1 -L2 /2 width=1 by lsuba_pair/
+#L1 #L2 #W #V #l1 #H #_ #_ #_ #_ #IHL12
+elim (shnv_inv_cast … H) -H #HW #HV #H
+lapply (H 0 ?) // -l1 #HWV