M. Gelfond and H. Przymusinska, Towards a theory of elaboration tolerance: logic programming approach, J. Software Eng. Knowledge Eng. 6(1) (1996) 89--112.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....theories which both have a conditional open definition for the same predicate, if the conditions don t overlap. This can be seen as a form of reasoning by cases, because, both theories give a definition for p in a different case. The compositionality issue is also studied in [1] 9] 15] 4] [10] and [12] For more references and a detailed discussion on theory composition, we refer to [17] A survey of the compositionality issue in logic programming is given in [5] As we already mentioned, applying the p opening operator or the conditional p opening operator on a theory, can be seen as ....

M. Gelfond and H. Przymusinska. Towards a Theory of Elaboration Tolerance: Logic Programming Approach. to appear in Journal on Software and Knowledge Engineering.

....two theories which both have a conditional open definition for the same predicate, in case the conditions don t overlap. This can be seen as a form of reasoning by cases (both theories give a definition for p in a different case) The compositionality issue is also studied in [1] 9] 15] 5] [10] and [12] For more references and a detailed discussion on theory composition, we refer to [19] A survey of the compositionality issue in logic programming is given in [6] As we already mentioned, applying the p opening operator or the conditional p opening operator on a theory, can be seen as ....

M. Gelfond and H. Przymusinska. Toward a Theory of Elaboration Tolerance for Logic Programs. International Journal on Software and Knowledge Engineering, 6(1):89--112, 1996.

..... This can be proven by induction on the length of the formula , using theorem 6.3. Conservative extensions were studied by Lifschitz and Turner in the context of disjunctive logic programming with classical negation [16] by Gelfond and Przymusinska in the context of extended logic programming [13] and in the context of epistemic specifications [14] 6.3 Hierarchical and acyclic programs The last results concern hierarchical and acyclic programs. For more details about this kind of programs, see [17] and [1] We just give their definitions. Definition 6.1 A logic program T d is ....

....The syntactic composition operator in OLP FOL is not always compositional and it should not be. As opposed to most of the works about compositionality, this paper considers logic programs which may contain negation in the body of their clauses. In section 6. 2 we mentioned three works [16] [13] and [14] which also allow negation. Other exceptions which also consider negation are [12] 20] 8] However, either they consider a weaker compositional semantics based on completion semantics [20] or the results are restricted either to hierarchical dependencies between modules, as in [12] ....

M. Gelfond and H. Przymusinska. Towards a Theory of Elaboration Tolerance: Logic Programming Approach. to appear in Journal on Software and Knowledge Engineering.

....values should not depend (or at least, depend as little as possible) on whether we input 15.0, 14.2, or 15.8. In more general terms, we want a small modification of the input not to lead to a major change in the plan. This requirement is called elaboration tolerance (see, e.g. McCarthy 1990) and (Gelfond Przymusinska 1995)) In view of this requirements, it is necessary to take into consideration that after each measurement (in particular, after each measurement of time) we know not the exact value of the measured quantity, but a set of possible values of this quantity. What kind of set can it be It is definitely ....

M. Gelfond and H. Przymusinska, "Towards a theory of elaboration tolerance: logic programming approach ", Intl. Journal of Software Engineering and Knowledge Engineering (a Special Issue on Knowledge Representation Methods), 1995 (to appear).

....is then gradually transformed by implementors into an executable program satisfying the specification. The process will of course normally require more than one iteration. There are many languages which can be used during various stages of this transformation. This paper adopts the view from [26] where the authors argue that for a rather broad class of knowledge representation problems the process of representing knowledge can be divided into three (mutually dependent) parts: Elaboration of a natural language description of the domain can be done in a language of functional ....

..... On the second stage implementors of the system are given the functional specification f constructed during the first stage of the process. Now they are confronted with the task of representing f in a logical language with a precisely described entailment relation. Gelfond and Przymusinska [26] advocate the use of a language A Prolog of logic programs with two types of negation and the answer set semantics. The choice is determined by the ability of A Prolog to represent default assumptions, i.e. statements of the form Elements of the class A normally (typically, as a rule) have ....

[Article contains additional citation context not shown here]

M. Gelfond and H. Przymusinska, Towards a theory of elaboration tolerance: logic programming approach, J. Software Eng. Knowledge Eng. 6(1) (1996) 89--112.

....is then gradually transformed by implementors into an executable program satisfying the specification. The process will of course normally require more than one iteration. There are many languages which can be used during various stages of this transformation. This paper adopts the view from [24] where the authors argue that for a rather broad class of knowledge representation problems the process of representing knowledge can be divided into three (mutually dependent) parts: ffl Elaboration of a natural language description of the domain can be done in a language of functional ....

....ffl On the second stage implementors of the system are given the functional specification f constructed during the first stage of the process. Now they are confronted with the task of representing f in a logical language with a precisely described entailment relation. Gelfond and Przymusinska [24] advocate the use of a language A Prolog of logic programs with two types of negation and the answer set semantics. The choice is determined by the ability of A Prolog to represent default assumptions, i.e. statements of the form Elements of the class A normally (typically, as a rule) have ....

[Article contains additional citation context not shown here]

M. Gelfond and H. Przymusinska. Towards a theory of elaboration tolerance: logic programming approach. Int'l Journal of Software Engineering and Knowledge Engineering, 6(1):89-112, 1996.

....we need to define the state of the world at a given moment in terms of its initial (known) state. The restriction to functional problems allows us to start the programming process with formalizing a natural language description of a problem in terms of functional specifications (f specifications) [GP96] functions which map collections of facts about known relations from the domain into collections of facts about new, defined relations. Such specifications can be defined by a specifier directly in a simple set theoretic language, or they can be built from previously defined specifications with ....

....with the help of specification constructors simple mappings from specifications to specifications. After the construction of an f specification f the designer of the system is confronted with the task of representing f in a logical language with a precisely described entailment relation. [GP96] advocates the use of a language L of logic programs with two types of negations and the answer set semantics. The choice is determined by the ability of L to represent default assumptions, i.e. statements of the form Elements of the class A normally have property P , epistemic statements P is ....

[Article contains additional citation context not shown here]

M. Gelfond and H. Przymusinska. Towards a theory of elaboration tolerance: logic programming approach. Int'l Journal of Software Engineering and Knowledge Engineering, 6(1):89-112, 1996.

....l and hence the interpolation T should entail l with X as the input. 12 It is interesting to study how the meaning of a general or an extended logic program changes if other parameter and or values are chosen while keeping an identical set of rules. Some answers to this question can be found in [GP96]. Proposition 3.1 An extended logic program T interpolates a general logic program Pi iff the following conditions are satisfied: 1. Equivalence) For every X 2 Dom( Pi) Pi(X) T (X) 2. Monotonicity) T is monotonic, i.e. for every X 1 ; X 2 P , if X 1 X 2 then T (X 1 ) T (X 2 ) 3. ....

....as an interpolation of a class of general logic programs ; the class obtained by adding any subset of the input atoms to the program. This way of looking at it is very much similar to the query expansion formulation. The other way to look at it is based on the concept of elaboration tolerance [GP96]. Intuitively, an elaboration tolerant representation of a specification requires only a small change in the representation when the specification is modified slightly. With respect to this paper the change in specification that happens during interpolation is the removal of the Close World ....

M. Gelfond and H. Przymusinska. Towards a theory of elaboration tolerance: Logic programming approach. To appear in Journal of Software Engineering and Knowledge Engineering, 1995

....is complementary to the work on program development in Prolog (see for instance [Dev90] and doesn t depend on any particular algorithm for executing logic programs. Instead it concentrates on the earlier stages of the program development. We will build on some basic ideas and results from [GP96] where the authors argue that the process of representing knowledge in LP can be divided into three (mutually dependent) parts: Elaboration of a natural language description of the domain, which leads to a precise mathematical characterization S of the statements which are true in the domain. ....

....the entailment relation of T . An inference mechanism associated with T can be used for rapid prototyping. Design of an efficient program Pi computing (or approximating) the entailment relation of T . Pi will be a logic program whose construction from T can be partially automated. In [GP96] the authors suggest that, at least in some cases, a formal (elaborated) specification of the domain can be obtained from specifications of its parts by applying certain operators on specifications called specification constructors and that a better understanding of these operators can ....

M. Gelfond and H. Przymusinska. Towards a theory of elaboration tolerance: logic programming approach. International Journal of Software Engineering and Knowledge Engineering, 6(1):89-112, 1996.

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