fact: Definition Book_2_10 : (exists a : A, (exists b : B a, (C (a; b)))) <~> (exists (p : exists a : A, B a), (C p)).
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)