after Damion Dooley Damion Dooley's note: Intention is to have it be the inverse of "before". This allows axioms like "B after A" to be placed in class B, rather than having to phrase them as "A before B" in class A. I believe time dependency relations (conditions) don't imply existence by themselves. If B after A, and B exists, this doesn't necessarily mean that A exists, only that if A does exist, it must be before B. To add that extra existence implication probably requires the "causally downstream of" and "immediately causally downstream of" RO relations, in a closed system where B cannot exist any other way. T1 after t2 iff:= t2 before_or_simulataneous_with t1 and not (t1 simultaeous_with t2) before requires discussion