Definition smash_hrel : hrel (X × Y) := λ xy₁ xy₂, xy₁ = xy₂ ∨ (product_point_coordinate xy₁ × product_point_coordinate xy₂).
Require Import UniMath.MoreFoundations.All. Require Import UniMath.CategoryTheory.Core.Categories. Require Import UniMath.CategoryTheory.DisplayedCats.Core. Require Import UniMath.CategoryTheory.DisplayedCats.Structures.CartesianStructure. Require Import UniMath.CategoryTheory.DisplayedCats.Structures.StructureLimitsAndColimits.