Branching Space- Time, Modal Logic and the Counterfactual Conditional
By Thomas Muller
The paper gives a physicist's view on the framework of branching space-time (Belnap, Synthese 92 (1992), 385–434). Branching models are constructed from physical state assignments. The models are then employed to give a formal semantics for the modal operators possibly and necessarily and for the counterfactual conditional. The resulting formal language can be used to analyse quantum correlation experiments. As an application sketch, Stapp's premises LOC1 and LOC2 from his purported proof of non-locality (Am. J. Phys. 65 (1997), 300–304) are analysed.