Zulip Chat Archive
Stream: new members
Topic: factorise (?) quantifier in a goal
Alice (Nov 14 2020 at 10:45):
If i have a goal like : (∀ (n : ℕ), p1(n)) ∧ (∀ (n : ℕ), p2(n))
, can i have ∀ (n : ℕ), p1(n) ∧ p2(n)
Or is there a way to intro n
in both.
Ruben Van de Velde (Nov 14 2020 at 10:50):
Try:
example (p q : ℕ → Prop) : (∀ n, p n) ∧ (∀ n, q n) ↔ (∀ n, p n ∧ q n) := by library_search
Johan Commelin (Nov 14 2020 at 10:50):
split
and then intro
in both branches. You can avoid repetition using split; intro
Ruben Van de Velde (Nov 14 2020 at 10:51):
Though Johan's approach is probably simpler; with mine you'd need to do intro
and then split
after
Alice (Nov 14 2020 at 10:58):
Yeah but I need the intro
to work with hypothesis and I don't want to repeat all that work so I prefer your approach,
library_search
give me forall_and_distrib.symm
and it's what I want.
Last updated: Dec 20 2023 at 11:08 UTC