English
Lift on a two-argument function descends through the localization to a function on LocalizedModule S M.
Русский
Подъем по двум аргументам спускается через локализацию на LocalizedModule S M.
LaTeX
$$$\\text{liftOn}_2 : (M \\times S) \\to (LocalizedModule S M) \\to (LocalizedModule S M) \\to α$$$
Lean4
/-- If `f : M × S → M × S → α` respects the equivalence relation `LocalizedModule.r`, then
`f` descents to a map `LocalizedModule M S → LocalizedModule M S → α`.
-/
def liftOn₂ {α : Type*} (x y : LocalizedModule S M) (f : M × S → M × S → α)
(wd : ∀ (p q p' q' : M × S), p ≈ p' → q ≈ q' → f p q = f p' q') : α :=
Quotient.liftOn₂ x y f wd