Definition θ {B C:category} (F : [B, C]) (X : [B, [C^op, HSET]]) : hSet := ( ∑ x : θ_1 F X, θ_2 F X x ) % set.
Require Import UniMath.Foundations.Preamble. Require Import UniMath.CategoryTheory.Core.Categories. Require Import UniMath.CategoryTheory.Core.Isos. Require Import UniMath.CategoryTheory.Core.Functors. Require Import UniMath.CategoryTheory.RepresentableFunctors.Precategories. Require Import UniMath.MoreFoundations.Tactics.