Substructural Observed Communication Semantics
  
  Substructural Observed Communication Semantics
  Proceedings
  
  
  
  
  Combined 27th International Workshop on Expressiveness in Concurrency and 17th Workshop on Structural Operational Semantics
  EXPRESS/SOS 2020
  
  OnlineAugust 31, 2020
  
  Ornela Dardha and Jurriaan Rot
  Electronic Proceedings in Theoretical Computer Science 322
  
  
  
  
  
  
  
  August 27, 202069–78
  
10.4204/EPTCS.322.7
Session-types specify communication protocols for communicating processes, and session-typed languages are often specified using substructural operational semantics given by multiset rewriting systems. We give an observed communication semantics for a session-typed language with recursion, where a process’s observation is given by its external communications. To do so, we introduce fair executions for multiset rewriting systems, and extract observed communications from fair process executions. This semantics induces an intuitively reasonable notion of observational equivalence that we conjecture coincides with semantic equivalences induced by denotational semantics, bisimulations, and barbed congruences for these languages.