Predicate settings

A predicate is an attribute entity described by schema datoms. Its settings determine how Claimframe stores values and derives structural conflicts.

Value cardinality

Setting	Meaning
One value	The subject has at most one current value for this predicate. A later value retracts the prior current value.
Many values	The subject may have multiple current values for this predicate.

Changing cardinality from one to many is allowed. Changing an established predicate from many to one is rejected; create a new predicate when that semantic change is required.

Uniqueness

Setting	Meaning
No uniqueness	Values may repeat without a uniqueness conflict.
Identity unique	A matching value identifies the same entity.
Value unique	A value may identify at most one entity.

Uniqueness may be added only when current data has no collisions. Conversion directly between identity and value uniqueness is rejected. Removing uniqueness is allowed.

Collection semantics

Setting	Meaning
Set	Values are unordered and deduplicated within a transaction.
List	Values preserve order and duplicates.

Changing set semantics to list semantics is allowed. Changing list semantics back to set semantics is rejected because it could discard meaningful order or duplicates.

Value type

Predicates may contain entity references or scalar strings, instants, booleans, doubles, or keywords. Changing the value type of an established predicate is rejected.

Claim-reference and conflict predicates

A claim-reference predicate targets an assertion transaction rather than an ordinary domain entity. A conflict predicate marks that relationship as explicit disagreement. Built-in predicates such as disputes and contradicts use these semantics.

These settings affect conflict detection throughout the vault. Review current data and intended meaning before changing them.

If an incompatible schema change is necessary, create a new predicate and leave the old predicate available for historical claims.