Zulip Chat Archive
Stream: general
Topic: Induction on list
Yury G. Kudryashov (May 04 2020 at 02:55):
Can I emulate the following equation compiler induction
theorem mythm : ∀ (l : list α), p l
| [] := p0
| [a] := p1
| (a::b::l) := p2 (mythm l)
using induction
tactic? Or should I add a lemma list.induction_on2 : ∀ l, C [] → C [a] → (∀ a b l, C l → C (a::b::l)) → C l
?
Yury G. Kudryashov (May 04 2020 at 02:56):
In my specific example I get l
as a result of rcases
so I can't use equation compiler directly (or I don't know how to do it).
Mario Carneiro (May 04 2020 at 03:40):
You could do strong induction on the length of the list
Last updated: Dec 20 2023 at 11:08 UTC