Relation _SIDE-CHAIN

Arity: 2
Domain: Atomic-unit
Subrelation-Of: _atomic-chain, _open
Axioms:
(=> (_Side-Chain ?A ?B)
    (Exists (?Y)
            (And (Atomic-Unit ?B)
                 (_Atomic-Chain ?B True)
                 (Has-Attached ?B ?A)
                 (Larger ?B ?A))))