Zulip Chat Archive
Stream: lean4
Topic: simplify the context of a hole before displaying it?
Jason Gross (Mar 06 2021 at 16:32):
I have a hole where Lean says "don't know how to synthesize placeholder" and lists a bunch of things in the context. I want to run the equivalent of Coq's simpl
tactic in the context and see the result. (I'd be willing to explicitly name the things I want to unfold if that's better, and, in this case, I'd also be fine with fully normalizing everything). How do I do this?
Leonardo de Moura (Mar 06 2021 at 16:55):
Have you tried to use tactic mode? Suppose you have a hole _
that cannot be synthesized, you can replace it with (by done)
, where done
is a tactic that fails when there are unsolved goals. Then, you can use tactics to simplify the context.
Example: (by clear h; simp; done)
. Note that simp
is not Coq simpl
since it will use theorems marked with [simp]
as rewriting rules, but you can use simp only
instead. Btw, simp only [foo]
unfolds foo
. simp only [foo] at h
unfolds foo
at hypothesis h
.
Jason Gross (Mar 08 2021 at 14:11):
I'm now trying this out; thanks!
Last updated: Dec 20 2023 at 11:08 UTC