lean-ja / lean-ja/lean-by-example
`#reduce` のページの説明が怪しい
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- Dominant language
- Lean
- Stars
- 188
- Forks
- 15
- Avg merge
- 9h 8m
- Merged PRs (30d)
- 6
Description
実際、Lean の型チェッカは再帰的な定義を受け付けないように設計されています。なぜかというと、再帰的な定義を（制限なしに）許すと矛盾が簡単に示せてしまうからです。
ほんまか？ちょっと不適切では？（なぜなら、停止性が分かっているのであればカーネル内で再帰的な形で保持したとしても問題はないから）
どちらかというと、信頼できる基盤に「再帰」という概念が入っていないということではないだろうか…。
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
Start with the page explaining #reduce and review the quoted claim about recursive definitions against Lean's behavior and trusted-kernel model. Done means the explanation accurately describes the role of termination and recursion without asserting that the type checker simply rejects recursive definitions.
Written by the indexing model from the issue text.
Assessment
- Domain
- documentation
- Issue type
- Documentation
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Quiet
- Clarity
- Mostly clear
- Newbie friendliness
- 48/100