English
For any f, composing with the identity on the right yields f itself.
Русский
Любой f, композиция с идентичностью справа даёт сам f.
LaTeX
$$$\\forall f:\\mathrm{BoundedLatticeHom}(\\alpha, \\beta):\\ (\\mathrm{BoundedLatticeHom.id}\\,\\beta).\\mathrm{comp}\\ f = f$$$
Lean4
@[simp]
theorem cancel_right {g₁ g₂ : BoundedLatticeHom β γ} {f : BoundedLatticeHom α β} (hf : Surjective f) :
g₁.comp f = g₂.comp f ↔ g₁ = g₂ :=
⟨fun h => BoundedLatticeHom.ext <| hf.forall.2 <| DFunLike.ext_iff.1 h, fun h => congr_arg₂ _ h rfl⟩