English
In LocallyFiniteOrder, the order-preserving embedding addMonoidHom G agrees with the plain additive monoid hom; i.e., the two notion align on the underlying map.
Русский
В LocallyFiniteOrder вложение addMonoidHom G согласуется с простым моноидом сложения; т.е. две концепции совпадают по базовой карте.
LaTeX
$$$$ \operatorname{orderAddMonoidHom} G = \operatorname{addMonoidHom} G. $$$$
Lean4
/-- The canonical embedding (as an ordered monoid hom) from a linearly ordered cancellative
group into `ℤ`. This is either surjective or zero. -/
def orderAddMonoidHom : G →+o ℤ where
__ := addMonoidHom G
monotone' a b
hab := by
obtain ⟨b, rfl⟩ := add_left_surjective a b
replace hab : 0 ≤ b := by simpa using hab
suffices 0 ≤ addMonoidHom G b by simpa
simp [addMonoidHom, hab]