proposition: Theorem Book_1_12_part1 : forall A B, A -> (B -> A).
proof: Proof. intros ? ? a ?. exact a. Defined.
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)