Weakly True Concurrency and Its Logic
  We firstly find the existence of silent event $\tau$ in true concurrency (named weakly true concurrency) by defining weakly true concurrent behaviors and weakly true concurrent logics. Based on Paolo Baldan and Silvia Crafa's comprehensive work on (strongly) true concurrency, we find the correspondence between weakly true concurrent equivalences and weakly true concurrent logics. 
Yong Wang
cs.LO