fact: Definition i2cons {a : A} {n} {l : Vector.t A n} {b : B a} {il : ilist2 l} (c : C b) (il2 : i2list il) : i2list (icons2 b il) := {| prim_fst := c; prim_snd := il2 |}.
imports: Coq.Lists.List Coq.Strings.String Coq.Arith.Arith Fiat.Common.ilist Fiat.Common.ilist2