Definition section_nat_trans_assoc {F1 F2 F3 F4: section_disp} (F12 : section_nat_trans_disp F1 F2) (F23 : section_nat_trans_disp F2 F3) (F34 : section_nat_trans_disp F3 F4) : section_nat_trans_comp F12 (section_nat_trans_comp F23 F34) = section_nat_trans_comp (section_nat_trans_comp F12 F23) F34.
Require Import UniMath.Foundations.Sets. Require Import UniMath.MoreFoundations.All. Require Import UniMath.CategoryTheory.Core.Categories. Require Import UniMath.CategoryTheory.DisplayedCats.Core.