AI Tool Profile
Lean
An open-source programming language and proof assistant with kernel checking.
Before you buy
Best for: Technical creators formalizing claims and checking proof artifacts with pinned dependencies.
Price: Canada/CAD: C$0 Apache-2.0 software; compute and setup separate
Included: The local toolchain supports formal proofs; current Lean includes lake comparator and lake check for validation workflows.
Main limits: Formal acceptance is relative to the statement and allowed axioms. It does not certify that a manuscript was formalized faithfully; memory can stop a run before a verdict.
What Kingy showed: The October 6 Lean 4.34.1 pilot accepted the Abhyankar–Sathaye target twice; four other attempts hit the fixed seven-GiB cap and remained unassessed.
Buying details checked 2026-10-22 with region and currency stated above. Historical demonstrations and the broader fact ledger keep their own dates.
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Coverage describes this profile, not a product score or a current price guarantee.
Kingy AI Product Facts
Lean
Current statusUnknown
- Company
- Not yet reviewed
- Primary job
- Not yet reviewed
- Audience
- Not yet reviewed
- Evidence
- Source-backed; coverage expanding
- Latest source check
- October 23, 2026
See all tracked product factsPricing, platforms, dependencies, data claims, regions, and timeline
Sources and checks
- Coverage
- 1 of 87 tracked fields currently verified
- Sources
- 1
Source-check dates apply to the tracked facts. Editorial updates elsewhere on this page may have a different date.
Plans and pricing units
Not yet structured in this Kingy record.
Where it runs
- Availability
- Not yet reviewed
Stack and integrations
- Model / provider dependencies
- Not yet reviewed
- Integrations
- Not yet reviewed
Data and regions
- Vendor data-use claim
- Not yet reviewed
- Vendor retention claim
- Not yet reviewed
- Regions
- Not yet reviewed
Launch and latest material update
- Launch
- Not yet reviewed
- Latest material update
- Not yet reviewed
Review history
- Lean — Product Facts updated
Kingy published an approved change to this Product Facts record.
View published revision - Lean — Product event recorded
Kingy recorded a product event. This entry does not verify every claim in the profile.
View published revision
Which plan is worth considering
Canada/CAD: C$0 Apache-2.0 software; compute and setup separate. The local toolchain supports formal proofs; current Lean includes lake comparator and lake check for validation workflows.
Limits that affect the purchase
Formal acceptance is relative to the statement and allowed axioms. It does not certify that a manuscript was formalized faithfully; memory can stop a run before a verdict. The pilot incurred US$0 paid-service expenditure, excluding hardware and electricity. The pilot pinned 42 dependency revisions and changed two toolchain files. Current toolchain behavior requires its own validation.
What the existing demonstration shows
The October 6 Lean 4.34.1 pilot accepted the Abhyankar–Sathaye target twice; four other attempts hit the fixed seven-GiB cap and remained unassessed. Twenty-one controls behaved as expected. This was local consistency on one machine, not independent mathematical replication. This describes the dated retained Kingy record, not a new product test. See the retained Kingy demonstration.
Sources and buying-review date
Buying details checked October 22, 2026. Plan research uses current official sources; demonstration descriptions use the retained Kingy record and any captured creator chapters. No new subscription, paid generation or checkout was performed. The buying-review date does not renew every claim in the broader facts ledger.
- Official plans and current offer
- Current integrated comparator guidance
- Related Kingy article
- Original Kingy demonstration
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Launch History
No structured launch records are linked to this tool yet.