J. A. Robinson. Logic and logic programming. Communications of the ACM, 35(3):40--65, March 1992.  Home/Search   Document Not in Database   Summary   ACM   TOC   Related Articles   Check

....their predecessors and then developing theories which match the new reality which has been created; computer engineering attempts to provide ecient implementations of the abstractions. No better example of this can be given than the developments relating to 64 A recent survey is contained in [Rob92] Alan Robinson also wrote the key paper [Rob65] 32 communication based concurrency. One of the rst steps away from shared variable concurrency was in the languages which provided queued message passing (e.g. KM77, Mac79] some hint of the history of process algebras is discussed above in ....

J. A. Robinson. Logic and logic programming. Communications of the ACM, 35(3):40-65, March 1992.

....and proved that, contrary to what happens in other P Complete problems, such as MCV, input depth does not influence the complexity of MGU . As a matter of fact, MGU(k depth) has been proved in P Complete for any k 1. This does not contradict the pathological nature of the worst inputs [Yas84, Rob92] and the experimental results collected in [HJ87] seem to confirm that the worst inputs are rarely met in real applications. But it definitely rejects the assumption that the complexity of parallel unification is precisely measured by the depth of the term graphs [HJ87] Nevertheless, we ....

J.A. Robinson. Logic and logic programming. Comm.ACM, 35(3):40--65, 1992.

....to something and a path from that something to c. There is an edge from a to b. Is there a path from b to c 1 Note that this informal description is given top down and requires you to remember the definition of an argument , which is used twice This description basically follows that given in [22]. 3 fib(0,1) fib(1,1) fib(A,B) fib( A,1) C) fib( A,2) D) B, C,D) Figure 2: A declaration of the Fibonacci sequence. This is a finite description of a (countably) infinite graph. There is a path from b to c if there is an edge from b to c. There is an edge from b to c, so there is a ....

J.A. Robinson. Logic and logic programming. Communications of the ACM, 35(3):40--65, March 1992.

....Even so, there is some sort structure maintenance that we may perform to reduce the cost of sort reasoning. If we determine that a sort s is empty or non empty, then we can assert this information in the sort context. We refer to this as sort memoing, since it is akin to memoing in OLDT resolution [16]. If sort reasoning is performed in localized areas of the sort structure, then this enhancement may result in improved performance at the cost of additional storage (in the worst case, one conjunctive sort is added to the context for any query) 5 Tractable subcases Many knowledge representation ....

J. A. Robinson. Logic and logic programming. Communications of the ACM, 35(3):40--65, March 1992.

....of the approach: it is shown on one representative example how the method can be used to detect (and to correct) errors in logic programs. Main lines of future research are given. 1 Introduction Automated Deduction and Logic Programming have numerous and deep connections (see for example [ROB83, ROB92, WM91]) Although each of these two fields has its own specific aims, they often provides to each other useful ideas and techniques. The aim of this work is to show how a model building method (developed by the authors since 1990 in order to be used in Automated Deduction) can be profitably used in ....

J.A. ROBINSON. Logic and Logic Programming. Communications of the ACM, 35(3):40--65, March 1992.

....design is unification 1 . Unification is an operation that supports the incremental 1 Let S be a set of expressions. When a substitution Theta transforms every expression in S into the same expression, Theta is said to unify S (or to be a unifier of S) and the set S is said to be unifiable [13]. solution of systems of constraints as new constraints are added. During the analysis of a sentence, unification is used to ensure that the constraints associated with its constituent phrases are compatible as specified by the rules of grammar. 2.2 Overview of the CLE Components The following ....

J.A. Robinson. "Logic and Logic Programming". Communications of the ACM, 35, 1992.

....abstractions for terms and term unification, and does not resort to any specific reduction control strategy. The abstraction on both data and control makes our system suitable in any applicative context where unification is required. 1 Introduction Since 1965, when J. A. Robinson [Robinson 65, Robinson 92] defined it as the substitution rule for resolution, unification has been widely used in several areas of computer science, e.g. programming languages, automated reasoning and artificial intelligence [Siekmann 90] Several algorithms have been proposed to improve the complexity and efficiency of ....

J.A. Robinson, Logic and Logic Programming, Comm. ACM 3, 35, 1992, 40-65.

....Even so, there is some sort structure maintenance that we may perform to reduce the cost of sort reasoning. If we determine that a sort s is empty or non empty, then we can assert this information in the sort context. We refer to this as sort memoing, since it is akin to memoing in OLDT resolution [125]. If sort reasoning is performed in localized areas of the sort structure, then this enhancement may result in improved performance at the cost of additional storage (in the worst case, one conjunctive sort is added to the context for any query) 7.4.1 Complexity of Sort Reasoning We now prove ....

J. A. Robinson. Logic and logic programming. Communications of the ACM, 35(3):40--65, March 1992.

....is presented and validated in the next section. 4. Typing inference in TA ( This section presents an algorithm to extract the principal recursive typing scheme of a process. We rely on the existence of a procedure to unify labelled (possibly regular infinite) trees. According to Robinson [19] such an algorithm was hit independently by Huet [11] Baxter [2] and Robinson [18] See [19] for an illustrated description of the algorithm. 4.1 The TA algorithm Given a process P , the algorithm TA either succeeds producing a typing 0 such that ( P 0 or, fails. When TA(P ) succeeds, it ....

....presents an algorithm to extract the principal recursive typing scheme of a process. We rely on the existence of a procedure to unify labelled (possibly regular infinite) trees. According to Robinson [19] such an algorithm was hit independently by Huet [11] Baxter [2] and Robinson [18] See [19] for an illustrated description of the algorithm. 4.1 The TA algorithm Given a process P , the algorithm TA either succeeds producing a typing 0 such that ( P 0 or, fails. When TA(P ) succeeds, it produces a principal typing for P , and if TA(P ) fails, there is no well typing for P . We ....

J.A. Robinson. Logic And Logic Programming. Communications of the ACM, 35(3):40--65, March 1992.

....limitations on the use of parallelism to speed up the static analysis of programs. However, itmay well be possible to use parallelism to achieve useful speedups on the kinds of staticanalysis problems that actually arise in practice cf. Robinson scomments on the Dwork KanellakisMitchell result [30]. The gadgets used in the constructions in Sections 3 and 4 have some similarities to the ones used in the proofs that the unification problem [4] and the left linear semi unification problem [7] are log space complete for P. Landi and Ryder have also investigated the computational complexity of ....

Robinson, J.A., "Logic and logic programming," Commun. of the ACM 35(3) pp. 40-65 (March 1992).

....work. 2.1 Historical Background As a field of study, it is generally agreed that logic programming began in the early 1970 s as an outgrowth of both mathematical logic and more recent automated theorem proving. Several excellent histories of these fields and logic programming exist, including [vH67, Dav63, Kow88, LMR92, Rob92]. We will touch on some of the more important and relevant milestones. Logic has been a field of study for many centuries. Perhaps the most famous logician from antiquity is Aristotle (384 322 B.C. who systematized and taught logic in ancient Greece. Modern logic can trace its origin to ....

J.A. Robinson. Logic and logic programming. Commun. ACM, 35(3):40--65, 1992.

....of a simplifiable and coherent relation are due to Huet. I simply adapted them to the kinded setting. A crucial point is the closing of a kinding under an equivalence relation, without which the results on unifiability could not be obtained. The original fast unification algorithm is said [8, 52] to have been discovered independently by Huet [33] Robinson [51] and Baxter [9] The kinded unification algorithm is an adaptation of Huet s algorithm, using transformation rules in the style of Gallier and Snyder [20] When compared with Huet s algorithm, the present algorithm has one more ....

....Hartmanis, editors, 3rd European Symposium on Programming, volume 432 of LNCS, pages 1 35. Springer Verlag, May 1990. 8] Jonas Barklund. Parallel Unification. PhD thesis, Uppsala University, 1990. 9] L. D. Baxter. The Complexity of Unification. PhD thesis, University of Waterloo, 1976. Cited in [52]. 10] G erard Berry and G erard Boudol. The chemical abstract machine. In 17th ACM Symposium on Principles of Programming Languages, pages 81 94. ACM Press, 1990. Also in Theoretical Computer Science, 96:217 248, 1992. 11] G erard Boudol. Some chemical abstract machines. INRIA Sophia ....

John A. Robinson. Logic and logic programming. Communications of the ACM, 35(3):40-- 65, March 1992.

.... The original resolution principle is due to Robinson [46] For a full description of Logic Programming, see, for example, 35] For a slightly anecdotal paper by Robinson himself about Logic Programming, including historical background and detailed descriptions of resolution and unification, see [47]. 2.2 Program Structure In this section we discuss the structure of CLP programs. The term constraint is used as it is defined in Section 1.2. Pi is the set of predicate symbols usable by the 4 Selective Linear Resolution for Definite Clauses program. An atomic formula or atom is a ....

J. Robinson. Logic and logic programming. Comunications of the ACM, 35(3):40--65, 1992.

....von Neumann Computers [Backus 78] d) Miranda [Turner 90] e) Why Functional Programming is Useful [Hughes 90] f) Denotational Semantics [Tennent 76] 5. Logic Programming (a) Prolog and Logic [Clocksin Mellish 84, Clocksin 87] b) Implementing Prolog [Roy Despain 92] c) Logic Programming [Robinson 92] d) Constraint Logic Programming [Cohen 90, Lassez 87, Colmerauer 87] ....

Robinson, J. A. Logic and logic programming. Comm. of the ACM, 35(3):41--58, March 1992.

No context found.

J. A. Robinson. Logic and logic programming. Communications of the ACM, 35(3):40--65, March 1992.

No context found.

J.A. Robinson. Logic and Logic Programming. Communications of the ACM, 35(3):41--65, 1992. 211

No context found.

Robinson, J. A. Logic and Logic Programming. Communications of the ACM 35, 3(1992), 40-64.

No context found.

Robinson, J.A. (1992) "Logic and Logic Programming," Communications of the ACM 35.3: 40-65.

No context found.

Robinson, J. A. Logic and Logic Programming. Communications of the ACM, July 1992.

No context found.

Robinson, J. A. Logic and Logic Programming. Communications of the ACM, July 1992.

No context found.

J. A. Robinson. Logic and logic programming. Communications of the ACM, 35(3):40--65, March 1992.

No context found.

Robinson, J.A. (1992) "Logic and Logic Programming," Communications of the ACM 35.3: 40-65.

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