lean-ja / lean-ja/lean-by-example
HEq を紹介する
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コード例
- Dominant language
- Lean
- Stars
- 188
- Forks
- 15
- Avg merge
- 9h 8m
- Merged PRs (30d)
- 6
Description
「のちのち型が等しいことが分かるが、しかしステートメントの時点では型が等しいことがわからないもの」が等しいと言いたいときに使う、というのが本筋なのではないか
example (p q : Prop) (h₁ : Decidable p) (h₂ : Decidable (p ∧ q)) : (p ↔ q) → h₁ ≍ h₂ := by
grind
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 HEq example in issue #1973 and review the repository's existing documentation examples to find the appropriate place for this explanation. Done means introducing HEq, explaining that it expresses equality when type equality is not yet known at the statement, and including the shown Lean example.
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
- Quiet
- Clarity
- Mostly clear
- Newbie friendliness
- 50/100