lean-ja / lean-ja/lean-by-example
`#guard` のよくあるエラー
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宣言的コマンド
- Dominant language
- Lean
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- 188
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- 15
- Avg merge
- 9h 8m
- Merged PRs (30d)
- 6
Description
自前で定義した型について #guard を使用しようとすると，DecidableEq のインスタンスがないのでエラーになる
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 by reproducing the reported error with #guard and a user-defined type, focusing on the missing DecidableEq instance. Done means adding a clear explanation of this common error and the documented way to address it; no file or test is named in the issue.
Written by the indexing model from the issue text.
Assessment
- Domain
- documentation
- Issue type
- Documentation
- Difficulty
- 2/5
- Estimated time
- 1-3 hours
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 35/100