Inference Web Browser -- Membership Rule (Declarative Rule)

Name: Membership Rule
Description in English:
This proof step indicates that, in JTP's frame system, a specific Value Collection contains the value in question.
A Value Collection can be thought of as the set of values of ?x that satisfy a triple of the form (property subject ?x), or of the form (property ?x value).
Given a triple (property subject value) this proof step could represent the inference that ?x=value belongs to the Value Collection (property subject ?x), or the inference that ?x=subject belongs to the Value Collection (property ?x value).
Example in English:
Given the triple (subClassOf SHELLFISH SEAFOOD) derive that ?x=SEAFOOD is a member of the Value Collection (subClassOf SHELLFISH ?x).