lean-ja / lean-ja/lean-by-example
partial_fixpoint を使って「停止すれば不動点を返す不動点コンビネータ」を定義できるか？
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- Dominant language
- Lean
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- 188
- Forks
- 15
- Avg merge
- 9h 8m
- Merged PRs (30d)
- 6
Description
不動点コンビネータは型付きラムダ計算ではそのままの形では定義することができないのだが、partial_fixpoint を用いて「終了しないケース」を無視すれば動作するものを作れるのではないだろうか？
この可能性を調べてみたい。
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 file, test, or entry point is named. Start by locating the project's existing treatment of partial_fixpoint and related fixed-point examples. Done means determining whether the proposed combinator can be defined and documenting the construction or the reason it cannot.
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
- Quiet
- Clarity
- Needs clarification
- Newbie friendliness
- 25/100