P. Brisset, T. Fruhwirth, P. Lim, M. Meier, T. Le Provost, J. Schimpf, and M. Wallace. ECL 3.5 Extensions User Manual. ECRC Munich Germany, December 1995. http://www.ecrc.de/eclipse/html/extroot/extroot.html.  Home/Search   Document Not in Database   Summary   Related Articles   Check

.... build a new CS, extend the CS with new constraints, specialize the CS for a particular application, combine constraint solvers. Our proposal to overcome this problem is a high level language especially designed for writing constraint solvers, called constraint handling rules (CHRs) [Fru92, Fru93a, Fru93b, Fru94, B 94, FrHa95]. With CHRs, one can introduce user defined constraints into a given high level host language. In this extended abstract the host language is Prolog, a CLP language with equality over Herbrand terms as the only built in constraint. We claim that using our logic based language allows for reasoning ....

....P is a conjunction of universally quantified clauses. A predicate definition for p is the set of all clauses in a program with the same predicate p in the head. A CLP clause is an implication H B 1 : Bn . 2 A third, hybrid kind as well as options and more declarations are described in [B 94]. Since we assume that a predicate definition defines a predicate completely, we strengthen the above using Clark s completion. Let H 1 : B 11 ; Bn1 ; H s : B 1s ; B ns ; 1 s) be the clauses of the predicate definition for p. Then their logical reading is: H (H = H 1 ....

[Article contains additional citation context not shown here]

P. Brisset et al., ECLiPSe 3.4 Extensions User Manual, ECRC Munich, Germany, July 1994.

.... generate and test search. It can be hard to believe that it works . Examining the behaviour of the program can help them with the latter problem. However, the bare Prolog trace is even worse than the code with respect to the first one. For example, a typical line of trace looks like: 16 8[4] call call( didbetter(M1C1, M2C1, friend(N1, C1, S1) friend(N2, C2, S2) friend(N3, C3, S3) nameis(M1C1, michael) sport(M1C1, basketball) nationality(M2C1, american) When analysing the program one can notice that, in order to give a first approximation of the program behaviour, ....

....Opium, a hard coded tracer could be easily implemented. CHR execution model. As already mentioned a CHR program contains both constraint rules and plain Prolog code. The model joins the Prolog model and new ports to cover the handling of constraint rules. The following description is adapted from [4]. add A new constraint is added to the constraint store. already in A constraint to be added was already present. try rule A rule is tried. delay rule The last tried rule cannot fire because the guard did not succeed. fired rule The last tried rule fires. try label A label declaration is ....

P. Brisset, T. Fruwirth, P. Lim, M. Meier, T. Le Provost, J. Schimpf, and M. Wallace. -- Eclipse 3.4 - extensions user manual. -- Technical report, ECRC, January 1994.

....is hidden and, for this reason, such solvers are called black boxes. An alternative approach, called the glass box approach, allows the user to control the constraint solver at a more detailed level [vHE 94] We consider here two black box constraint languages (ECL i PS e [AGG 95, BRI 95] and Oz [SMO 95] and two glass box languages (clp(FD) COD 96, DIA 94] and CHR [FRU 94, BRI 95] comparing both their expressiveness and their efficiency. We chose these particular languages since all provide support for FD and boolean constraints, were free and easy to obtain and are being ....

.... approach, called the glass box approach, allows the user to control the constraint solver at a more detailed level [vHE 94] We consider here two black box constraint languages (ECL i PS e [AGG 95, BRI 95] and Oz [SMO 95] and two glass box languages (clp(FD) COD 96, DIA 94] and CHR [FRU 94, BRI 95] comparing both their expressiveness and their efficiency. We chose these particular languages since all provide support for FD and boolean constraints, were free and easy to obtain and are being very popular within the logic constraint community. In addition, ECL i PS e includes all the ....

[Article contains additional citation context not shown here]

BRISSET P., FR UHWIRTH T., LIM P., MEIER M., LE PROVOST T., SCHIMPF J. and WALLACE M., ECL i PS e 3.5 Extensions User Manual, ECRC Munich Germany, December 1995.

....combining the declarativity of LP with the efficiency of CS. However most CLP languages are not extensible: Constraint solving is usually hard wired in a built in constraint solver written in a low level language. They do not allow for user defined constraints. Constraint handling rules (CHR) [4, 8] are a high level language extension to write constraint systems. CHR support rapid prototyping of application oriented constraint systems by providing executable specifications and efficient implementations due to an optimizing compiler. CHR allows for specialization, modification and combination ....

....constraints the MRA can account for the statistical imprecision and also compute the estimated rent even in the presence of partial answers. Our approach was to first implement the tables, rules and formulas of the Mietspiegel with high level and declarative programming in ECL i PS e [4], ECRC s advanced constraint logic programming platform, as if the provided data was precise. Because of the declarativity of ECL i PS e it was easy to express the contents of the MS. Then we added constraints to capture the imprecision due to the statistical method and incompleteness in case ....

Brisset, P., Fr uhwirth, T., Lim, P., Meier, M., Provost, T. L., Schimpf, J., and Wallace, M. ECL i PS e 3.4 Extensions User Manual. ECRC Munich Germany, July 1994.

....assignment has been used in a number of systems developed at ECRC [22, 15, 26, 16] In particular, the time stamping scheme [1] developed in the context of the Constraint Logic Programming CHIP has been quite influential. As for extensible unification, the interface provided by ECLiPSe [23, 7], to date the most sophisticated, is also based on destructive assignment. Finally, in many Prolog systems (e.g. BinProlog [29] ECLiPSe [17] SICStus [14] XSB [28] the built in predicate setarg 3, which makes it possible to destructively replace the argument of a compound term, provides a ....

....of the extension. The predicate combineattributes 2 just needs two arguments, namely the boxed attributes. By convention, the second argument, for instance, always contain the boxed attribute of the unbound variable, to be used for further updating. The extensible unification interface of ECLiPSe [6, 7] is based on such a scheme (although the details of the interface are quite different) 4.3 Dropping the substitution slot The idea is to represent an attributed variable by an attributed variable reference (tag AVR) whose value field gives the address of the attribute slot. Handling attributed ....

P. Brisset, T. Fruhwirth, P. Lim, M. Meier, T. Le Provost, J. Schimpf, and M. Wallace. -- ECLiPSe 3.4 - Extensions User Manual. -- ECRC, Munich, Germany, July 1994.

No context found.

P. Brisset, T. Fruhwirth, P. Lim, M. Meier, T. Le Provost, J. Schimpf, and M. Wallace. ECL 3.5 Extensions User Manual. ECRC Munich Germany, December 1995. http://www.ecrc.de/eclipse/html/extroot/extroot.html.

....The implementation scheme given in this technical report is somewhat biased towards the most advanced implementation of CHRs utilizing advanced features of ECL i PS e . In the appendix a comprehensive generic example of the result of compilation in the actual CHRs library of ECL i PS e [B 95] is given and explained. It differs from the translation scheme described by a number of optimizations, mainly to exploit head matching and produce more deterministic code. We also show the result of applying the transformations proposed in this paper to a simple example in appendix 3. Last but ....

.... The first implementation of CHRs in 1991 was an interpreter written in ECRC s constraint logic programming platform ECL i PS e (see appendix 1) At the moment, there exist two sequential implementations, one prototype in LISP [Her93] and one fully developed CHRs library in ECL i PS e [B 95]. At DFKI Saarbrucken, an implementation of CHRsin the concurrent object oriented language OZ [SmTr94] is on the way. The LISP implementation does not provide for simpagation rules, but offers some interesting extensions. First, rules can be given priorities (encoded as integers) Second, ....

[Article contains additional citation context not shown here]

P. Brisset et al., ECL i PS e 3.5.1 Extensions User Manual, ECRC Munich, Germany, April 1995.

No context found.

P. Brisset, T. Fruhwirth, P. Lim, M. Meier, T. Le Provost, J. Schimpf, and M. Wallace. ECLiPSe 3.5 extension user manual. CHIC Deliverable D.6.2.4, ECRC, Arabellastr 17, Munich, Germany, 1995.

No context found.

BRISSET P., FR UHWIRTH T., LIM P., MEIER M., LE PROVOST T., SCHIMPF J. and WALLACE M., ECL 3.5 Extensions User Manual, ECRC Munich Germany, December 1995.

No context found.

P. Brisset, T. Fruhwirth, P. Lim, M. Meier, T. Le Provost, J. Schimpf, and M. Wallace. ECL i PS e 3.4 Extensions User Manual. ECRC Munich Germany, July 1994.

No context found.

BFL + 94. P. Brisset, T. Fruhwirth, P. Lim, M. Meier, T. Le Provost, J. Schimpf, and M. Wallace. ECL i PS e 3.4 Extensions User Manual. ECRC Munich Germany, July 1994.

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