Deadlock-freeness of hexagonal systolic arrays

With the re-emergence of parallel computation for technical applications in these days also the classical concept of systolic arrays is becoming important again. However, for the sake of their operational safety, the question of deadlock must be addressed. For this contribution we used the well-known Roscoe-Dathi method to demonstrate the deadlock-freeness of a systolic array with hexagonal connectivity. Our result implies that it is theoretically safe to deploy such arrays on various platforms. Our proof is valid for all cases in which the computational pattern (input-output-behaviour) of the array does not depend on the particular values (contents) of the communicated data.http://www.elsevier.com/locate/iplmv201

On a semantic definition of data independence

A variety of results which enable model checking of important classes of infinite-state systems are based on exploiting the property of data independence. The literature contains a number of definitions of variants of data independence which are by syntactic restrictions in particular formalisms. More recently, data independence was defined for labelled transition systems using logical relations, enabling results about data independent systems to be proved without reference to a particular syntax. In this paper, we show that the semantic definition is sufficiently strong for this purpose. More precisely, it was known that any syntactically data independent symbolic LTS denotes a semantically data independent family of LTSs, but here we show that the converse also holds

On a Semantic Definition of Data Independence

A variety of results which enable model checking of important classes of infinite-state systems are based on exploiting the property of data independence. The literature contains a number of definitions of variants of data independence which are by syntactic restrictions in particular formalisms. More recently, data independence was defined for labelled transition systems using logical relations, enabling results about data independent systems to be proved without reference to a particular syntax. In this paper, we show that the semantic definition is suciently strong for this purpose. More precisely, it was known that any syntactically data independent symbolic LTS denotes a semantically data independent family of LTSs, but here we show that the converse also holds

On a semantic definition of data independence

A variety of results which enable model checking of important classes of infinite-state systems are based on exploiting the property of data independence. The literature contains a number of definitions of variants of data independence, which are given by syntactic restrictions in particular formalisms. More recently, data independence was defined for labelled transition systems using logical relations, enabling results about data independent systems to be proved without reference to a particular syntax. In this paper, we show that the semantic definition is sufficiently strong for this purpose. More precisely, it was known that any syntactically data independent symbolic LTS denotes a semantically data independent family of LTSs, but here we show that the converse also holds