Recognises a fact type with clashing modalities

What it means

One fact type constrained both alethically (cannot be otherwise) and deontically (ought to be so). One of the two is misclassified.

How it is assessed

Flags the deficient case and passes the acceptable one. Deficient: `it is necessary that each IBAN is unique` and `it is obligatory that each IBAN is unique` on the same fact type Acceptable: Decide using Witt's test: data can contain duplicates, so it is deontic — obligatory, and enforced (`ANO-008`)

Builds on

Explains alethic and deontic modality of rulesK-352 · Knowledge

Needed by

None