fact: Definition concat_left {A : Type} {x y : A} (z : A) (p : x = y) : (y = z) -> (x = z) := fun q => p @ q.
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)