fact: Definition i3cons2 {a : A} {n} {l : Vector.t A n} {b : B a} {il : ilist3 l} (c : C b) (il3 : i3list2 il) : i3list2 (icons3 b il) := {| prim_fst := c; prim_snd := il3 |}.
imports: Coq.Lists.List Coq.Strings.String Coq.Arith.Arith Fiat.Common.ilist Fiat.Common.ilist3