A causal semantics for CCS via rewriting logic

We consider two operational semantics for CCS defined in the literature: the first exploits proved transition systems (PTS) and the second rewriting logic (RL). We show that the interleaving interpretation of both semantics agree, in that they define the same transitions and exhibit the same non-deterministic structure. In addition, we study causality in CCS computations. We recall its treatment via PTS, exhibiting the notion of causality presented in the literature, and we show how to recast it in the RL semantics via suitable axioms. Also in this case, the two semantics agree.