English
An induction principle: if there is a HasUncurry β γ δ, then there is a HasUncurry (α → β) (α × γ) δ with uncurry defined by uncurry f (a, c) = f a c.
Русский
Принцип индукции: если существует раскрытие HasUncurry β γ δ, то существует раскрытие HasUncurry (α → β) (α × γ) δ, заданное uncurry f (a, c) = f a c.
LaTeX
$$$ (\\operatorname{uncurry} f)(a,c) = (f a) c$$$
Lean4
/-- An involution commutes across an equality. Compare to `Function.Injective.eq_iff`. -/
protected theorem eq_iff {x y : α} : f x = y ↔ x = f y :=
h.injective.eq_iff' (h y)