fact: Definition presheaf_morphism {T : algebraic_theory} (P P' : presheaf T) : UU := presheaf_cat T ⟦P, P'⟧.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Core.NaturalTransformations UniMath.Combinatorics.StandardFiniteSets UniMath.AlgebraicTheories.AlgebraicTheories UniMath.AlgebraicTheories.Presheaves UniMath.AlgebraicTheories.PresheafCategoryCore UniMath.AlgebraicTheories.IndexedSetCategory