lean-ja / lean-ja/lean-by-example
lemmaではできなくてsimprocが必要な例
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メモ
- Dominant language
- Lean
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- 188
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- Merged PRs (30d)
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Description
282271** said:
Nash|240862** [said](https://leanprover.zulipchat.com/#narrow/channel/113488-general/topic/.22Missing.20Tactics.22.20list/near/500866120):
````quote
Surely we should be able to crush a goal like this with a single tactic?
````
How were you expecting this tactic to determine what value of `a'` it should use for the forward direction? Do we want an aesop rule that scans for `∃ a', ... ∧ a' = a ∧ ...`?
Actually I want a simproc that does this. I've wanted this since before simprocs existed, I think it's one of the best examples of something you can't do with lemmas alone (and in particular, it's an isabelle simproc since forever)
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
No files or tests are named. Start by reviewing the linked Zulip discussion and the issue's simproc proposal, then establish the intended behavior and implementation entry point. Done requires an agreed design and a working simproc for the described existential-equality case.
Written by the indexing model from the issue text.
Assessment
- Domain
- compilers
- Issue type
- Feature
- Difficulty
- 5/5
- Estimated time
- Over a week
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 15/100