Groote and Vaandrager introduced the tyft format, which is a congruence format for strong bisimulation equivalence. This article proposes additional syntactic requirements on the tyft format, extended with predicates, to obtain a precongruence format for language preorder.

This paper studies the (in)equational theory of simulation preorder and equivalence over the process algebra BCCSP. We prove that in the presence of a finite alphabet with at least two actions, the (in)equational theory of BCCSP modulo simulation preorder or equivalence does not have a finite basis. In contrast, in the presence of an alphabet that is infinite or a singleton, the equational theo...

One-counter nets (OCN) are Petri nets with exactly one unbounded place. They are equivalent to a subclass of one-counter automata with just a weak test for zero. Unlike many other semantic equivalences, strong and weak simulation preorder are decidable for OCN, but the computational complexity was an open problem. We show that both strong and weak simulation preorder on OCN are PSPACE-complete....

Extended Abstract ABSTRACT We recast Milner's work on nite delay in synchronous CCS by giving a denota-tional semantics for admissibility of innnite computations on a biinite domain K. Using Abramsky's SFP domain D for bisimulation we obtain a fully abstract model D K for an operational preorder which generalizes Milner's fortiica-tion and whose restriction to nite behavior corresponds to Abram...

A general method is established to derive a ground-complete axiomatization for a weak semantics from such an axiomatization for its concrete counterpart, in the context of the process algebra BCCS. This transformation moreover preserves ω-completeness. It is applicable to semantics at least as coarse as impossible futures semantics. As an application, groundand ω-complete axiomatizations are de...

A key problem in mixing operational (e.g., process-algebraic) and declarative (e.g., logical) styles of specification is how to deal with inconsistencies arising when composing processes under conjunction. This article introduces a conjunction operator on labelled transition systems capturing the basic intuition of “a and b = false”, and considers a naive preorder that demands that an inconsist...

The uniform verification problem for parameterized systems is to determine whether a temporal property is true for every instance of the system which is composed of an arbitrary number of homogeneous processes. We consider some aspects of the inductionbased technique which assumes the construction of finite invariants of such systems. An invariant process is one which is greater (with respect t...

In order to address this problem, our algorithm uses the rst element of preorder node sequence to nd the root of tree, and locate the root in the inorder node sequence. Then, in inorder sequence, everything on the left side of the root element is the inorder node sequence of the left subtree and everything on the right side of of the root element is the inorder node sequence of the right tree. ...

If ≤ is a preorder on a set P and p0 ≤ p1, we say that p1 is an extension of p0. Recall that a preorder is separative if and only if whenever p1 is not an extension of p0 there is an extension of p1 which is incompatible with p0. We say that P = (P,≤) is a forcing notion (also forcing poset) if ≤ is a separative preorder with minimal element 0P. Note that if P is separative and p1 p̌0 ∈ Ġ then p...