fact: Definition Book_1_5_ind (A B : Type) (C : Book_1_5_sum A B -> Type) (f : forall a, C (inl a)) (g : forall b, C (inr b)) : forall x : Book_1_5_sum A B, C x := fun x => match x with | inl a => f a | inr b => g b end.
imports: HoTT(Basics Types HProp HSet Projective TruncType Truncations Modalities.Notnot Modalities.Open Modalities.Closed BoundedSearch Equiv.BiInv Spaces.Nat Spaces.Torus.TorusEquivCircles Metatheory.Core Metatheory.FunextVarieties)