English
Let α be a type, p a proposition, q : α → Prop. Then (p → ∀ x, q x) is equivalent to ∀ x, p → q x.
Русский
Пусть α — множество, p — proposition, q: α → Prop. Тогда (p → ∀ x, q x) эквивалентно ∀ x, p → q x.
LaTeX
$$$$\\left(p \\rightarrow \\forall x, q\\,x\\right) \\Longleftrightarrow \\forall x, p \\rightarrow q\\,x.$$$$
Lean4
/-- We intentionally restrict the type of `α` in this lemma so that this is a safer to use in simp
than `forall_swap`. -/
theorem imp_forall_iff {α : Type*} {p : Prop} {q : α → Prop} : (p → ∀ x, q x) ↔ ∀ x, p → q x :=
forall_swap