Elementary realization rather than endpoint interpretation

A causal relation between every input and output does not by itself imply the common-rendezvous hypothesis. We do not use the proposition as a universal localization theorem. QCA localizability and quantum causal graph dynamics provide stronger structural theorems under their own hypotheses SchumacherWerner,ArrighiNesmeWerner,ArrighiMartiel. They are comparison results, not unproved substitutes here.