lean-ja / lean-ja/lean-by-example
`move_mul` タクティクを紹介する
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タクティク
- Dominant language
- Lean
- Stars
- 188
- Forks
- 15
- Avg merge
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- Merged PRs (30d)
- 6
Description
結合法則と交換法則を使って順序変換を行える。gcongr などと組み合わせると便利
theorem extracted_1 {a b c : ℝ} (apos : a > 0) (bpos : b > 0) (cpos : c > 0)
(goal : (1 / a + 1 / b + 1 / c) * (a + b + c) ≥ 9) :
(1 / a + 1 / b + 1 / c) * (a * b * c) * (a + b + c) ≥ 9 * (a * b * c) := by
-- linarith
-- nlinarith
move_mul [a, b, c]
gcongr
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 or test is named. Start by locating the appropriate documentation or example page in lean-by-example, then add a Japanese introduction to the move_mul tactic using the provided theorem example. Done means the explanation and example are included in the relevant documentation and the documentation still builds successfully.
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
- Mostly clear
- Newbie friendliness
- 45/100