Characterizing bisimilarity of value-passing parametrised processes

AbstractSymbolic transition graphs of Hennessy and Linextended with assignments are used to represent parametrisedvalue-passing processes. Semantics appealing to thenotion of state is introduced for the symbolic transition graphsand their extended version. Showing strong early bisimulation between finite symbolic transition graphs extended with assignments isreduced to solving sets of equations involving first-order state formulas

A non-Mixed-Term Inference System for Olderog Process Calculus

this report we are interested in the application area (cf. [Soko/lowski 94]) of communicating processes. In the literature, one can find many different specification systems for communicating processes. In our opinion, one of the most interesting ones is the process algebra and calculus of Olderog, presented for example in [Olderog 91]. The Olderog system is interesting because it is elegant, modular and, at the same time, quite powerful. Unfortunately there is one problem with it: the inference system for proving satisfaction uses a notion of mixed terms. Mixed terms are, as the name suggests, a mixture of specifications and constructions. Below we present a non-mixed term inference system for the Olderog calculus which is relatively sound and complete with respect to the original proof system for j?. We assume that the reader is familiar with the Olderog approach. Throughout the report we use notation and notions from [Olderog 91]. 2 The Proof Syste

A Specification System for Parametric Concurrent Processes

A process algebra and readiness logic introduced by Olderog are extended to a framework in which processes parameterized with other processes can be specified, defined and verified. Higher order process-parameters are allowed. The formalism resembles typed lambda calculus built on top of a process algebra, where specifications play the role of types. A proof system for deriving judgements "parametric process meets a specification" is given. 1 Introduction A typical approach to software development is that of decomposition of large tasks into smaller subtasks. To formalize the decomposition principle, let us consider a set of constructions Constr (programs, processes, etc.), a set of specifications Spec, and satisfaction relation sat between constructions and specifications (sat can be given, for example, by a proof system). The triple (Constr ; Spec; sat) (1) will be referred to in the sequel as specification system (see [Soko/lowski 94]). The decomposition principle amounts to the r..

A Framework for Representing Parameterised Processes

We describe a faithful representation of value-passing recursive parametric CCS processes in Alf, an implementation of Martin-Lof's constructive type theory. The representation is interesting because we borrow as much as possible from Alf including the domain of value and state expressions and the ability to evaluate them. Usually substitution of either channel values for channel variables and processes for process variables play a necessary role in the semantics. However, substitution is also borrowed from Alf by using higher-order functions. The main importance of this representation is that it allows us to borrow Alf's off-the-shelf theorems about data types and provides a uniform setting for doing various kinds machine assisted proofs, such as bisimulation proofs, equational reasoning, verification of Hennessy-Milner logic formulas. 1 Introduction Machine checked proofs of CCS processes require finite representations of the processes. However, for infinite value and state domains,..

Hepatic Mitochondrial Redox Potential in Patients with Liver Metastatic Cancers and Circulatory Insufficiency

Arterial ketone body ratio (AKBR), which reflects hepatic intramitochodrial redox potential, was measured in 20 patients with Carcinoma hepatis metastaticum and good circulatory condition (group A), and 16 patients with Carcinoma hepatis metastaticum and chronic cardiogenic circulatory insufficiency (group B). Total ketone body concentration (TKB) and arterial oxygen tension (PaO2) was simultaneously determined. We have stated that AKBR values in both groups of patients were decreased below the normal level. AKBR values in group B were significantly lower than in group A. At the same time TKB values in both groups were statistically equal and significantly increased above the normal level. The levels of arterial oxygen tension (PaO2) in group A were physiologically high, whereas in group B were significantly decreased. Furthermore arterial oxygen tension of patients in group B correlated with AKBR values significantly. In group A we found statistically significant negative correlation between TKB and AKBR values. Our study indicate that the main mechanism which may explain the decrease of intrahepatic mitochondrial redox potential in patients with liver metastatic cancers and good circulatory condition, is the enhanced beta-oxidation of fatty acids, when the efficiency of NAD+ to NADH reduction in beta-oxidation pathway and tricarboxylic acid cycle is higher than re-oxidation of NADH to NAD+ in the oxidative phosphorylation. In patients with coexisting chronic cardiogenic circulatory insufficiency deprivation of blood oxygen supply initiate the irreversible dysfunction of oxidative phosphorylation