English
If f is injective, then orderHom f is injective.
Русский
Если f инъективно, то orderHom f инъективно.
LaTeX
$$$\\text{If } f \\text{ is injective, then } \\operatorname{orderHom} f \\text{ is injective}$$$
Lean4
@[to_additive]
theorem orderHom_injective {f : M →*o N} (h : Function.Injective f) : Function.Injective (orderHom f) :=
by
intro a b
induction a using ind with
| mk a
induction b using ind with
| mk b
simp_rw [orderHom_mk, mk_eq_mk, ← map_mabs, ← map_pow]
obtain hmono := (OrderHomClass.monotone f).strictMono_of_injective h
intro ⟨⟨m, hm⟩, ⟨n, hn⟩⟩
exact ⟨⟨m, hmono.le_iff_le.mp hm⟩, ⟨n, hmono.le_iff_le.mp hn⟩⟩