English
For f: M →* P and g: N →* P and x in FreeMonoid(M ⊕ N), lift f g (mk x) = FreeMonoid.lift (Sum.elim f g) x.
Русский
Для отображений f: M →* P и g: N →* P и элемента x ∈ FreeMonoid(M ⊕ N): lift f g (mk x) = FreeMonoid.lift (Sum.elim f g) x.
LaTeX
$$$ \mathrm{lift}(f,g)(\mathrm{mk}(x)) = \mathrm{FreeMonoid.lift}(\mathrm{Sum.elim} f g)(x) $$$
Lean4
@[to_additive (attr := simp)]
theorem lift_apply_mk (f : M →* P) (g : N →* P) (x : FreeMonoid (M ⊕ N)) :
lift f g (mk x) = FreeMonoid.lift (Sum.elim f g) x :=
rfl