Y. Gurevich. Evolving Algebras: A Tutorial Introduction. Bulletin of the European Association for Theoretical Computer Science, 43:264--284, February 1991.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....to model algorithm without encoding data structures and splitting execution steps. He observed that every conceivable data structure can be modeled as a Tarski structure, and every possible state change of the algorithm can be modeled by a set of explicit, pointwise changes to the structure. In [17, 18] a proof of the thesis for sequential algorithms is given, and in [5] the corresponding proof for parallel algorithms is shown. 18 This pure mathematical program, has been implicitly transformed in a computer science project, by defining a concrete rule language for defining the update sets. ....

Y. Gurevich. Sequential ASM Thesis. Bulletin of European Association for Theoretical Computer Science, (67):93--124, February 1999. Also Microsoft Research Technical Report No. MSR-TR-99-09.

....in polynomial time. On the other hand, it is known that if 24 MARTIN GROHE deciding isomorphism is NPTIME complete then the polynomial hierarchy collapses. Furthermore, the problem of finding a canonization function for isomorphism can be reduced to the problem of finding a complete invariant [36]. 6. FINITE VARIABLE LOGICS WITH COUNTING Although we can express important queries, such as connectivity of graphs, with few variables, our logics L k are very weak in another respect: They cannot count very far. Remember Example 3.8, where we have seen that the logic L k 1 cannot ....

Y. Gurevich. From invariants to canonization. Bulletin of the European Association for Theoretical Computer Science, 63:115--119, 1997.

....of full edged realistic languages and be useful to programmers for language engineering, without sacri cing a formal basis. It relies on context free grammars (EBNF) for the speci cation of syntax, nite state machines for graphically specifying control ow, and Abstract State Machines [7,19,23]. for specifying dynamic semantics. The formalism is supported by a tool suite called Gem Mex which helps in writing and maintaining a speci cation and then executing it to generate a prototypical programming environment for the speci ed language. The generated environment consists of a parser, an ....

Y. Gurevich. Sequential ASM Thesis. Bulletin of European Association for Theoretical Computer Science, (67):93-124, February 1999. Also Microsoft Research Technical Report No. MSR-TR-99-09.

....the language SPL. Section 4 de nes the abstract compilation of SPL programs to SPLM programs. Section 5 de nes the machine SPLM. Section 6 describes the initialization. Section 7 presents conclusions. Throughout this paper we assume the reader to be familiar with Gurevich s concept of ASMs (cf. [Gur95,Gur97,Gur99]) 2 Overview of the Formal SDL Semantics The de nition of the formal semantics of SDL is structured into the following major parts: grammar well formedness conditions transformation rules, and dynamic semantics The grammar de nes the set of syntactically correct SDL speci cations. ....

Yuri Gurevich. The sequential ASM thesis. Bulletin of the European Association for Theoretical Computer Science, 67:93-124, February 1999. Columns: Logic in Computer Science.

....a RAM in polynomial time p there is a RAM M inverting h such that for every RAM M 0 inverting h there is a constant c 0 with time M (y) c Delta(time M 0 (y) p(jM 0 (y)j) for every y in the range of h. Note that the brief note [9] contains no proof. Proofs of Theorem 1 can be found in [14, 6] (where the latter article uses the Kolmogorov Uspensky machine model also used in [9] It is noted in [14] that one can transfer the result to the Turing machine model if one replaces the term c Delta ( in the above theorem by c 0 Delta ( Delta log( To study the ....

Yuri Gurevich. The logic in computer science column. Bulletin of the European Association for Theoretical Computer Science, (35):71--82, 1988.

....Montages [28, 4] a language specification environment proposed recently by some of the authors. Montages can as well be seen as a combination of Attribute Grammars and Action Routines. For giving the actions, Montages use Abstract State Machine (ASM) rules. ASMs where introduced by Gurevich in [16, 18] to formally specify algorithms on arbitrary abstraction levels. There exist a number of case studies applying ASMs to the specification of programming languages. In the case of imperative and object oriented languages, these applications work in the same way as Action Routine specifications, but ....

Y. Gurevich. Sequential ASM Thesis. Bulletin of European Association for Theoretical Computer Science, (67):93--124, February 1999. Also Microsoft Research Technical Report No. MSR-TR-99-09.

....distributed termination detection algorithm originally invented by Dijkstra, Feijen, and van Gasteren. 1 Introduction In this paper we propose a methodology for the specification and verification of distributed algorithms using Gurevich s concept of Abstract State Machines (cf. Gur95] Gur97] [Gur99]) The development of distributed algorithms usually starts with an informal problem description (see figure 2) In order to get a mathematical model of the problem description at the starting point of construction one has to choose what often is called a ground model (cf. Bor99] or a ....

Yuri Gurevich. The sequential ASM thesis. Bulletin of the European Association for Theoretical Computer Science, 67:93--124, February 1999. Columns: Logic in Computer Science.

.... 3 3 Computations of EvAs 3 4 Constant Propagation 4 5 Macro Definitions 5 6 Unfolding Macros 5 7 Folding Macros 6 8 Flattening 7 9 Pass Separation 7 10 An Example 10 11 Implementation 12 12 Other Work 12 13 Conclusions 12 1 Introduction Evolving algebras (EvAs) have been proposed by Gurevich in [Gur91] and used by Gurevich and others to give the operational semantics of languages like Modula 2,Prolog, Occam and C. Borger and Rosenzweig s proof of the correctness of the Warren Abstract Machine is based on a slight variation of evolving algebras ( BR92] An evolving algebra may be tailored to ....

....halt(w) and halt(v) could not be true at the same time. Nevertheless heuristics can be used to decide, whether the conditions are mutually exclusive. But in general some conditions, which are mutually exclusive, can not be detected. Even checking mutual exclusion at run time is co NPcomplete ([Gur91]) 12 Other Work In [JS86] the authors use pass separation to generate a compiler and an abstract machine for a functional language from a specification of an abstract interpreter. The transformations are very sophisticated, but they are neither formally defined, nor is it likely that they can be ....

Yuri Gurevich. Evovling Algebras: a tutorial introduction. Bulletin of the European Association for Theoretical Computer Science, 43:264--284, 1991.

....in polynomial time. On the other hand, it is known that if 24 MARTIN GROHE deciding isomorphism is NPTIME complete then the polynomial hierarchy collapses. Furthermore, the problem of finding a canonization function for isomorphism can be reduced to the problem of finding a complete invariant [36]. 6. FINITE VARIABLE LOGICS WITH COUNTING Although we can express important queries, such as connectivity of graphs, with few variables, our logics L k are very weak in another respect: They cannot count very far. Remember Example 3.8, where we have seen that the logic L k 1 cannot ....

Y. Gurevich. From invariants to canonization. Bulletin of the European Association for Theoretical Computer Science, 63:115--119, 1997.

....semantics, which is implemented by the static link technique, uses the X which is declared in P. This, of course, is what a programmer expects to be the semantics of the access to X. Evolving algebras are a new concept for the description of operational semantics and abstract machines ( Gur88] [Gur91]) Its basic idea is to describe the behavior of the machine by a transition system with algebras as states. Each state represents the complete state of the computation. The use of evolving algebras has several advantages: ffl the usual definitions of machine state and transition relation can be ....

.... 2; X 0;1 =z; X 1;1 =0; X 1;2 =0; X 2;1 =1] X 0;1 ) reset( 1; reset( 2; X 0;1 =z; X 1;1 =0; X 1;2 =0; X 2;1 =0] X 0;1 ) reset( 1; X 0;1 =z; X 1;1 =0; X 1;2 =0] X 0;1 ) X 0;1 =z] X 0;1 ) z 2 Evolving Algebras The concept of evolving algebras was introduced in [Gur91] as a method for the description of operational semantics. An evolving algebra is the description of a transition system, where the states are algebras over a (first order) signature. Each state holds the information for a single step of the computation. Recently, evolving algebras were used for a ....

Y. Gurevich. Evolving Algebras: A Tutorial Introduction. Bulletin of the European Association for Theoretical Computer Science, 43:264--284, February 1991.

....has some nice properties, the most important of which include soundness and completeness. 1 Introduction Abstract State Machines (ASMs) formerly called Evolving Algebras, were introduced by Yuri Gurevich in the late eighties and early nineties as an alternative formal specification language (see [7, 8, 9]) ASMs are claimed to be easier to work with than other formal specification formalisms known from the literature. Egon Borger was one of the first to test the ASM methodology. He formalized the operational semantics of full Prolog (see e.g. 1, 2, 3, 4] Since then quite a lot of papers applying ....

Y. Gurevich. Evolving Algebras, a tutorial introduction. Bulletin of the European Association for Theoretical Computer Science, 43:264--284, February 1991.

....theory, and later developments in that field have found their way back to linguistics. But in addition, ideas originally developed for other applications have been incorporated into linguistic research. This paper considers the use of techniques from the theory of evolving algebras (see Gurevich [5]) in the development of syntactic formalisms. Our application of evolving algebras to grammatical formalisms may be viewed as part of several trends. First, there have been a number of formalisms proposed in the theoretical computer science literature for various kinds of machines which embody ....

....the correctness of algorithms and implementations. 2.1 Background on Evolving Algebras In this section we review the basics of the EA framework. For a more leisurely introduction (which contains a fuller discussion of the reasons for the EA approach to programming semantics) see Gurevich [5]. An evolving algebra is a many sorted, first order structure together with some transition rules. A many sorted, first order structure is just a family of sets (called universes) with functions between them. Typically these universes will be finite, and they will usually come with some basic ....

Y. Gurevich. Evolving algebras: a tutorial introduction. Bulletin of the European Association for Theoretical Computer Science, 43:264--286, 1991.

....discuss evolving algebras. The subject of evolving algebras was introduced by Yuri Gurevich around 1985 as a means of specifying operational aspects of computation at a level appropriate for reasoning about the system in question. Evolving algebras can be viewed as vast generalization of PDL (see [17]) It uses many sorted first order structures as the states of its structures, and in contrast to standard practice, the constant and function symbols are dynamic: they might change according to a set of transition rules. Although we can t give any formal details here, the evolving algebra ....

Y. Gurevich. Evolving algebras: A tutorial introduction. Bulletin of the European Association for Theoretical Computer Science, 43:264--286, 1991.

....transformation for evolving algebras is presented. It can be used to derive a compiler and abstract machine from an interpreter. All transformations are proven correct. Finally a comparison to other work is given. 1 Introduction Evolving algebras (EvAs) have been proposed by Gurevich in [Gur91] and used by Gurevich and others to give the operational semantics of languages like C, Modula2, Prolog and Occam. Borger and Rosenzweig s proof of the correctness of the Warren Abstract Machine is based on a slight variation of evolving algebras ( BR92] An evolving algebra may be tailored to ....

....Implementation All transformations in this paper can be automated, but testing the mutual exclusion of run time rules is not even decidable. Nevertheless heuristics can be used to decide, whether the conditions are mutually exclusive. Even checking mutual exclusion at run time is co NP complete ([Gur91]) 3 Other Work In [JS86] the authors use pass separation to generate a compiler and an abstract machine for a functional language from a specification of an abstract interpreter. The transformations are very sophisticated, but they are neither formally defined, nor is it likely that they can be ....

Yuri Gurevich. Evolving Algebras: a tutorial introduction. Bulletin of the European Association for Theoretical Computer Science, 43:264--284, 1991.

....processes. They can at once be viewed as abstract machines, and as formal specifications. Thus, the evolving algebra formalism combines two perspectives on computational processes: specification methods and computational models. Since evolving algebras were first proposed by Yuri Gurevich [Gur91][Gur95] they have been the subject of ongoing research. The graduation project, the results of which are presented in this thesis report, aimed to make a dual contribution to this research. On the one hand, an attempt has been made to advance the development of the theory of evolving algebras. On ....

....In the foregoing chapter, an informal description was given of evolving algebras. In this chapter, we will give a formal exposition of the core theory of evolving algebras. This account is based on two introductory articles written by Yuri Gurevich Evolving Algebras: A Tutorial Introduction [Gur91] and Evolving Algebras 1993: Lipari 2.1. Introduction 19 run transition graph program state transition ffl ffi fi fl ffl ffi fi fl ffl ffi fi fl ffl ffi fi fl i i i i i i) ffl ffi fi fl P P P P P Pq j j j Q Q Qs j j j Q Q Qs Figure 2.1: Definitional structure of the theory of ....

Yuri Gurevich. Evolving algebras, a tutorial introduction. Bulletin of the European Association for Theoretical Computer Science, 43:264 -- 284, February 1991.

....theory, and later developments in that field have found their way back to linguistics. But in addition, ideas originally developed for other applications have been incorporated into linguistic research. This paper considers the use of techniques from the theory of evolving algebras (see Gurevich [5]) in the development of syntactic formalisms. Our application of evolving algebras to grammatical formalisms may be viewed as part of several trends. First, there have been a number of formalisms proposed in the theoretical computer science literature for various kinds of machines which embody ....

....the correctness of algorithms and implementations. 2.1 Background on Evolving Algebras In this section we review the basics of the EA framework. For a more leisurely introduction (which contains a fuller discussion of the reasons for the EA approach to programming semantics) see Gurevich [5]. An evolving algebra is a many sorted, first order structure together with some transition rules. A many sorted, first order structure is just a family of sets (called universes) with functions between them. Typically these universes will be finite, and they will usually come with some basic ....

Y. Gurevich. Evolving algebras: a tutorial introduction. Bulletin of the European Association for Theoretical Computer Science, 43:264--286, 1991.

....an interpreter for the language of interest and to refine this in well motivated and understandable ways so as to arrive eventually at a description that is based on executing low level instructions on a corresponding abstract machine. We have used the abstract state machine formalism of Gurevich [Gurevich 91] as a specification language in this task. This formalism is especially suited to our task since it permits perspicuous yet mathematically precise description of machines to be provided at various levels of granularity. There is, furthermore, a well developed verification methodology that can be ....

....algebra A consists of a number of disjoint sets called universes and functions on the Cartesian product of these sets. The collection of these function symbols is referred to as the signature of A. A function of arity zero is called a distinguished element or constant. Following Gurevich [Gurevich 91] we assume that both the universes and the associated signature are fixed throughout the computation. Among the configurations, some are identified, as usual, as initial and final states. The following notation corresponding to universes will be useful: Definition 2.2. For any universe U , we ....

Yuri Gurevich. Evolving algebras. A tutorial introduction. Bulletin of the European Association for Theoretical Computer Science, 43:264--284, 1991.

No context found.

Y. Gurevich. Evolving Algebras: A Tutorial Introduction. Bulletin of the European Association for Theoretical Computer Science, 43:264--284, February 1991.

No context found.

Y. Gurevich. Evolving algebras: A tutorial introduction. Bulletin of the European Association for Theoretical Computer Science, 43:264--286, 1991.

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC