The loophole that is left proposes that a particle detector's settings may "conspire" with events in the shared causal past
of the detectors themselves to determine which properties of the particle to measure-a scenario that, however far-fetched, implies that a physicist running the experiment does not have complete free will in choosing each detector's setting.
Thus, an event e directly precedes an event e', if and only if no other event e" belonging to E exists, such that e" belongs at the same time to the causal future of e and to the causal past of e'.
Each bit in [PHI](p) identifies a message m in the causal past of p.
x will be some factor in the apparent causal past
of the measurement, perhaps something in the past of the measuring device or the experimenter, if one is directly involved.