lean-ja / lean-ja/lean-by-example
HasSubset 型クラス
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型クラス
- Dominant language
- Lean
- Stars
- 188
- Forks
- 15
- Avg merge
- 9h 8m
- Merged PRs (30d)
- 6
Description
/-- 集合の包含関係。`Subset s t` は数学における `s ⊆ t` に対応する。 -/
protected def Set.Subset (s t : Set α) : Prop := ∀ x, s x → t x
/-- `Subset s t` を `s ⊆ t` と書けるようになった。 -/
instance : HasSubset (Set α) := ⟨Set.Subset⟩
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
The issue only provides a Lean snippet defining Set.Subset and a HasSubset instance; no file, entry point, or test is named. Clarify where this example belongs and what the completed documentation should contain before starting, then verify the example builds in its intended location.
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
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 30/100