PLN (Probabilistic Logic Networks)
Responsible: Patrick Hammer, Peter Isaev, Nil Geisweiller
Hyperon's primary symbolic reasoning system for uncertainty. Represents beliefs with graded confidence, supports deductive/inductive/abductive reasoning, and leverages ECAN for computational tractability over massive Atomspaces.
</> Example Implementation
Probabilistic inference
Shows PLN's probabilistic deduction with strength-truth-values propagating through inheritance chains.
; PLN deductive reasoning with confidence
!(add-belief (Inheritance "Tweety" "Bird")
(stv 0.95 0.9))
!(add-belief (Inheritance "Bird" "Animal")
(stv 0.99 0.99))
; Deductive inference
!(pln-deduce
(Inheritance "Tweety" "Animal"))
; => (stv 0.94 0.89)
Technical Deep Dive: PLN Full — STV quantale formalism, backward chaining on MORK, factor-graph belief propagation, historical design decisions, and implementation findings.