A contradiction to settle
When a relation can have only one target at a time, a new target never silently replaces the old one: it becomes a contradiction, and a human decides.
Deciding
- Contradictions have their own filter in the Knowledge › To review queue.
- They are decided one by one: « Approve all » leaves them aside.
- A relation becomes exclusive when the ontology says so — « one target at a time »; Ailu suggests it, you decide.