Report Number: CS-TN-95-17
Institution: Stanford University, Department of Computer Science
Title: Ntyft/ntyxt Rules Reduce to Ntree Rules
Author: Glabbeek, R.J. van
Date: February 1995
Abstract: Groote and Vaandrager introduced the tyft/tyxt format for Transition System Specifications (TSSs), and established that for each TSS in this format that is well-founded, the bisimulation equivalence it induces is a congruence. In this paper, we construct for each TSS in tyft/tyxt format an equivalent TSS that consists of tree rules only. As a corollary we can give an affirmative answer to an open question, namely whether the well-foundedness condition in the congruence theorem for tyft/tyxt can be dropped. These results extend to tyft/tyxt with negative premises and predicates.