English
Symmetric counterpart: EqToHom hab op composed with homOfLE hbc equals homOfLE of the appropriate composite in the opposite setting.
Русский
Симметрично: EqToHom hab с чем-то сопоставляется с homOfLE в противоположном виде.
LaTeX
$$$\mathrm{eqToHom\_comp\_homOfLE\_op} : {X} \; (hab : a=b) (hbc : c \le b) \\Rightarrow \; \mathrm{CategoryTheory.opposite}.\mathrm{comp}(\mathrm{eqToHom}(hab), \mathrm{homOfLE}(hbc)) = \mathrm{homOfLE}(...)^{op}$$$
Lean4
@[simp, reassoc]
theorem eqToHom_comp_homOfLE_op {a b c : X} (hab : op a = op b) (hbc : c ≤ b) :
eqToHom hab ≫ (homOfLE hbc).op = (homOfLE (hbc.trans (le_of_eq (op_injective hab.symm)))).op :=
rfl