Recognises a cardinality rule stated from one end only
A cardinality rule stated from one end, leaving the other end unconstrained. The commonest cause of duplicates.
Can AI do this?
AI does this well Most of the tested AI models master this. 9 of 10 models master it.
| Model | Tier | Probability of mastery | Status |
|---|---|---|---|
| gemini-4-argon | Flagship | 99% | Mastered |
| gemini-3.1-pro-preview | Flagship | 99% | Mastered |
| gpt-6-astra | Flagship | 100% | Mastered |
| claude-fable-5-1 | Flagship | 100% | Mastered |
| gemini-3.8-flash | Mid tier | 99% | Mastered |
| gpt-6.1-sol | Mid tier | 99% | Mastered |
| claude-sonnet-5-5 | Mid tier | 99% | Mastered |
| gemini-3.5-flash-lite | Low cost | 43% | Not shown |
| gpt-6-luna | Low cost | 100% | Mastered |
| claude-haiku-5-5 | Low cost | 100% | Mastered |
Mastered means a probability of at least 90% that the model has this knobit, estimated from its graded answers. “Not shown” means the answers do not settle it either way. How the models are tested.
What it looks like in practice
Expected result: The unconstrained end and the rule for it
How it is assessed: Flags the deficient case and passes the acceptable one. Deficient: "Each account has exactly one IBAN" (nothing stops two accounts sharing one) Acceptable: Both: "each account has exactly one IBAN" and "each IBAN is held by at most one account"
Also known as: One direction only (data rule)
Related knobits
Builds on
All 28 knobits of Document data rules as SBVR fact types and rule statements.
Source: Review checklist 03-data-rules, row 18