fact: Fixpoint ith2_pair {m : nat} {As : Vector.t A m} {As' : Vector.t A' m} {il : ilist2 As} (ilp : ilist2_pair il As') (n : Fin.t m) {struct n} : C (Vector.nth As' n) (ith2 il n) .
imports: Coq.Lists.List Coq.Strings.String Coq.Arith.Arith Fiat.Common.ilist Fiat.Common.ilist2