Definition make_span_diagram {C : category } (a b c : C) (f : C ⟦a, b⟧) (g : C⟦a, c⟧) : diagram span_graph C. Proof. use make_diagram. - exact(three_rec a b c). - use three_rec_dep; use three_rec_dep; try exact(empty_rect _). + exact(unit_rect _ f). + exact(unit_rect _ g). Defined.
Require Import UniMath.Foundations.All. Require Import UniMath.MoreFoundations.All. Require Import UniMath.CategoryTheory.Core.Categories. Require Import UniMath.CategoryTheory.Limits.Graphs.Colimits. Require Import UniMath.Combinatorics.StandardFiniteSets. Require Import UniMath.Combinatorics.FiniteSets.