Relation DEPENDENTLY-ANTEDATES

Two entities whatsoever existing in disjoint time-spans, and the second depends on the first.
Arity: 2
Subrelation-Of: Antedates, Strictly-necessary-to
Axioms:
(<=> (Dependently-Antedates ?A ?B)
     (And (Antedates ?A ?B) (Strictly-Necessary-To ?A ?B)))