fact: Definition I1_λ : lambda 0 := abs (var (make_stn 1 0 (idpath true))).
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.Combinatorics.Tuples UniMath.Combinatorics.Vectors UniMath.Combinatorics.StandardFiniteSets UniMath.AlgebraicTheories.LambdaCalculus