lean-ja / lean-ja/lean-by-example
構造的再帰でないことを確かめる例
Open
Nobody has claimed this yet.
コード例
- Dominant language
- Lean
- Stars
- 188
- Forks
- 15
- Avg merge
- 9h 8m
- Merged PRs (30d)
- 6
Description
/-- 繰り返し自乗法のアルゴリズム -/
@[simp, grind]
def repeatedSquare (x : α) (n : Nat) : α :=
if n = 0 then
1
else if n % 2 = 0 then
(repeatedSquare (x * x) (n / 2))
else
x * (repeatedSquare x (n - 1))
termination_by structural n
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
Locate the repeatedSquare example from the issue in the repository and check it with Lean's termination checker. Determine what the example is intended to demonstrate about structural recursion; done when the example clearly reflects that intent and the surrounding documentation remains accurate.
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