The OrLink asserts a boolean-logic disjunction of propositions. OrLink can operate over predicates or concepts, but not between concepts and predicates.
In PLN the OrLink semantics corresponds to a fuzzy set union (accounting for confidence).
OrLink <TV> A B
where denotes the function associated to the fuzzy connector , usually .
Initially the OrLink is defined over concepts, but is overloaded to predicates as well, in that case the union is applied over the corresponding satisfying sets.
For instance one may express the OrLink between predicates like
OrLink <TV> PredicateNode "hard_working" PredicateNode "fortunate"
OrLink <TV> ConceptNode "hard_worker" ConceptNode "fortunate_people"