Zulip Chat Archive
Stream: new members
Topic: forall commutes with or
Raphael Appenzeller (Jul 29 2022 at 14:47):
I would like to use the following statement in a proof. I would have expected this to be in the library somewhere but library_search
was not successful. Is there a different version that I could use, or should this be added to the library?
lemma logic_helper (α β : Type*) (A : α → Prop ) (B : β → Prop): (∀ u : α , ∀ v : β , A u ∨ B v )
↔ (∀ u : α, A u) ∨ (∀ v : β , B v ) :=
begin
sorry,
end
Ruben Van de Velde (Jul 29 2022 at 14:53):
lemma logic_helper (α β : Type*) (A : α → Prop ) (B : β → Prop): (∀ u : α , ∀ v : β , A u ∨ B v )
↔ (∀ u : α, A u) ∨ (∀ v : β , B v ) :=
begin
simp_rw [←forall_or_distrib_right, ←forall_or_distrib_left],
end
Last updated: Dec 20 2023 at 11:08 UTC