 should hold for the TRL-function. On the other hand, they have argued that the combination of (TRL1) and (TRL2) is inconsistent with the very idea of branching time. The reason is that if (TRL1) and (TRL2) are both accepted, it follows from \(t_1 \lt t_2\) that \(t_2 \in \TRL(t_1)\) i.e., that all moments of time after \(t_1\) would have to belong to the thin red line through \(t_1\), which means that there will in fact be no branching at all. However, it is very hard to see why a true futurist would have to accept (TRL2), which seems to be too strong a requirement. Rather than (TRL2), the weaker condition (TRL2′) can be employed: