English
The canonical map on value groups induced by a coarsening of valuation rings.
Русский
Каноническое отображение на группы значений, индуцируемое упрощением оценок колец.
LaTeX
$$$mapOfLE(R,S,h): R.ValueGroup \to*₀ S.ValueGroup$$$
Lean4
/-- The canonical map on value groups induced by a coarsening of valuation rings. -/
def mapOfLE (R S : ValuationSubring K) (h : R ≤ S) : R.ValueGroup →*₀ S.ValueGroup
where
toFun := Quotient.map' id fun _ _ ⟨u, hu⟩ => ⟨Units.map (R.inclusion S h).toMonoidHom u, hu⟩
map_zero' := rfl
map_one' := rfl
map_mul' := by rintro ⟨⟩ ⟨⟩; rfl