Terminality implies non-signalling

@inproceedings{Coecke2014TerminalityIN,
  title={Terminality implies non-signalling},
  author={Bob Coecke},
  booktitle={QPL},
  year={2014}
}
  • B. Coecke
  • Published in QPL 14 May 2014
  • Computer Science
A 'process theory' is any theory of systems and processes which admits sequential and parallel composition. `Terminality' unifies normalisation of pure states, trace-preservation of CP-maps, and adding up to identity of positive operators in quantum theory, and generalises this to arbitrary process theories. We show that terminality and non-signalling coincide in any process theory, provided one makes causal structure explicit. In fact, making causal structure explicit is necessary to even make… 
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