- ∃∃I,K,V. |K| = n & L = K. ⓑ{I}V.
-#n * [ >length_atom #H destruct ]
-#L #I #V >length_pair /3 width=5 by ex2_3_intro, injective_S/
+ ∃∃I,K. |K| = n & L = K. ⓘ{I}.
+#n *
+[ >length_atom #H destruct
+| #L #I >length_bind /3 width=4 by ex2_2_intro, injective_S/
+]