M.A. Moshier and W. C. Rounds. A logic for partially specified data structures. In Proceedings of the 14th ACM Symposium on Principles of Programming Languages,pages156--167, 1987.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....and works on feature constraints rather than feature terms. Kasper [22] investigates the use of feature terms with implications (an implication S T is equivalent to :S tT ) for modeling systems in systemic grammar. He outlines a unification method for these terms. Moshier and Rounds [31] study a feature term logic that interprets negations intuitionistically. They prove that the satisfiability problem of this logic is PSPACE complete. Dawar and Vijay Shanker [8] investigate several possible interpretations of negation in feature terms using three valued logic. The linguistic ....

M. D. Moshier and W. C. Rounds. A logic for partially specified data structures. In Proceedings of the 14th ACM Symposium on Principles of Programming Languages, pages 156--167, Munchen, W. Germany, 1987.

.... this intuitive understanding not sufficient 10 Briscoe Copestake (1999) provide an interesting discussion of lexical rules in a typed default feature structure framework (Lascarides et al. 1996, Lascarides Copestake 1999) which is an extension of a Kasper Rounds logic (Rounds Kasper 1986, Moshier Rounds 1987, Carpenter 1992) The ontological assumptions and formal properties of a KasperRounds logic differ in crucial respects from those of an Attribute Value logic (Johnson 1988, Smolka 1988, King 1989) and King (1994) shows that only the latter is compatible with the assumptions of HPSG as proposed ....

Moshier, M. A. & Rounds, W. C., 1987. A Logic for Partially Specified Data Structures. In Proceedings of the 14th ACM Symposium on Principles of Programming Languages. M unchen. pp. 156--167.

....(1992) are therefore not required to be totally well typed or sort resolved. In the HPSG II setup partial information plays no role; the linguistic objects themselves are modelled by the sorted feature structures. This difference has consequences for the description language of Carpenter (1992) Moshier and Rounds (1987) show that in the setup of a KasperRounds logic, full classical negation as part of the description language destroys subsumption monotonicity on typed feature structures which Carpenter and others claim has to be upheld if feature structures are to model partial information. In the discussion of ....

....true or false of linguistic objects, not of feature structures which stand in a one to one relation with linguistic objects, as in HPSG II. Apart from the philosophical consequences (which will not be discussed here) this gap between HPSG II and King (1989) can 13 cf. Rounds and Kasper (1986) Moshier and Rounds (1987), and Carpenter (1992) 14 cf. Johnson (1988) Smolka (1988) and King (1989) 15 Note that the theories in an HPSG II architecture are formulated using implications on types; in fact, even stronger implicative statements with complex antecedents are used. We will see on pp. 15 of section ....

Moshier, M. A., and W. C. Rounds. 1987. A Logic for Partially Specified Data Structures. In Proceedings of the 14th ACM Symposium on Principles of Programming Languages. Munchen, Germany, 156-- 167.

....defined within a specific formal framework. Now, properties of classes of structures that are defined in some formal way are the provenance of Model Theory. It s not surprising, then, to find treatments of the meaning of such systems of constraints couched in terms of formal logic [KR86, MR87, KR90, GPC 88, Joh88, Smo89, DVS90, Car92, Kel93] More recently, the role of logic has begun to expand beyond just providing formal semantics for the constraints to provide the entire linguistic formalism. See, for instance, Joh89, Sta92, Cor92, BGMV93, BMV94, Kel93, Rog94, Kra95] and, ....

M. Drew Moshier and William C. Rounds. A logic for partially specified data structures. In ACM Symposium on the Principles of Programming Languages, 1987.

....in two respects: first, we add complements and nonsingleton sorts; and second, and maybe more important, we show that our open world semantics yields the same notion of subsumption and consistency as a closed world semantics using feature structures as fixed interpretation. Moshier and Rounds [16] generalize the formalism of Rounds and Kasper [21] by adding nonclassical negation. They show that the consistency problem of the extended logic is PSPACE complete. In contrast, classical negation, which underlies our logic, does not render the consistency problem any harder (it is already ....

M. D. Moshier and W. C. Rounds. A logic for partially specified data structures. In Proceedings of the 14th ACM Symposium on Principles of Programming Languages, pages 156--167, Munchen, W. Germany, 1987.

.... has emerged, but such systems have already provided interesting analyses of programming languages (Borger (1990) theory change (Gardenfors (1988) de Rijke (1994) anaphora and presupposition in natural language (Groenendijk and Stokhof (1991) Beaver (1994) and various syntactic formalisms (Moshier and Rounds (1987), Johnson and Moss (1994) What will ultimately emerge is unclear but I do think it s both interesting and important to get to grips with dynamic issues. Look, let s wrap things up here. As far as I m concerned, the most important point is the following. Logic is increasingly being influenced ....

Moshier, D., and Rounds, W., 1987, "A logic for partially specified data structures," pp. 156--167 in Proceedings of the 14th ACM Symposium on Principles of Programming Languages, Munich.

....method appears simple at first sight. For example, close the formulae under negation, and extend satisfaction classically so that a feature structure satisfies the negation of a formula iff the feature structure does not satisfy the formula. However, this apparent simplicity is deceptive. Firstly, [Moshier and Rounds 1987] showed that a KRL style logic with classical negation is not subsumption monotonic. Secondly, in order to deliver accurate representations of implicative information, the formalismmust meet the condition that some satisfier of a formula represents partial information about a linguistic entity iff ....

....the condition that some satisfier of a formula represents partial information about a linguistic entity iff no satisfier of the negation of the formula represents partial information about the entity. It is easy to show that a KRL style logic with classical negation does not meet this condition. [Moshier and Rounds 1987], Langholm 1989] and others have proposed various subsumption monotonic extensions of KRL with nonclassical negations, and these extensions easily adapt to EKR and LTFS, but it remains an open question whether any of these extensions can deliver accurate representations of implicative ....

M. Andrew Moshier and William C. Rounds. "A logic for partially specified data structures." Pages 156--167 of Proceedings of the 14th ACM symposium on principles of programming languages. 1987.

....quibble. In a Kasper and Rounds logic, many feature structures can satisfy a formula, but among the satisfiers is a so called most general satisfier or set of satisfiers, and each formula is taken to indicate the partial information represented by its most general satisfier or set of satisfiers. (Moshier and Rounds, 1987) shows that if a Kasper and Rounds logic is augmented with unrestricted classical implication then some formulae have no most general satisfier or set of satisfiers, and so fail to indicate a piece of partial information. Consequently, every Kasper and Rounds logic with implication employs either ....

....some formulae have no most general satisfier or set of satisfiers, and so fail to indicate a piece of partial information. Consequently, every Kasper and Rounds logic with implication employs either a nonclassical 6 I cite this as (Pollard and Sag, 1987) 12 PAUL JOHN KING implication as in (Moshier and Rounds, 1987) or a restricted classical implication as in (Carpenter, 1992) However, all of the constraints (Pollard and Sag, 1994) imposes on feature structures are classical implications, and some have a complexity that is difficult if not impossible to express within the strictures (Carpenter, 1992) ....

Moshier, M. D. and Rounds, W. C. (1987). A logic for partially specified data structures. In Proceedings of the 14th ACM Symposium on Principles of Programming Languages, pages 156--167, Munchen, Germany.

....specific formal framework. Now, for the most part, properties of classes of structures that are defined in a formal way like this are the provenance of Model Theory. It s not surprising, then, to find treatments of the meaning of such systems of constraints couched in terms of formal logic [KR86, MR87, KR90, GPC 88, Joh88, Smo89, DVS90, Car92, Kel93, RVSar] More recently, a number of people have noticed that, at least in some cases, extra logical mechanisms for combining constraints can be replaced by ordinary logical operations. See, for instance, Joh89, Sta92, Cor92, BGMV93, BMV94, ....

M. Drew Moshier and William C. Rounds. A logic for partially specified data structures. In ACM Symposium on the Principles of Programming Languages, 1987.

....[Pereira, 1987] is not problematic. In the existing unification based approaches, it is not possible to propagate negative constraints via unification without giving up partiality of feature structures or without admitting some unwanted sideeffects into the system [Kasper and Rounds, 1986] [Moshier and Rounds, 1987] [Johnson, 1988] Johnson, 1990] Dawar and Vijay Shanker, 1990] Carpenter, 1992] The UNO model shares many computational characteristics with the programming language LIFE [Ait Kaci and Richard Meyer and Peter Van Roy, 1993] because the efficiently computable calculus that underlies LIFE ....

Moshier, M. D. and Rounds, W. C. (1987). A logic for partially specified data structures. In 14-th Symposium on Principles of Programming Languages.

....HPSG 94. In particular, to ensure each formula has a most general satisfier, a Kasper and Rounds A Formalism for HPSG 94 3 logic must be subsumption monotonic: if a first feature structure satisfies a formula and subsumes a second feature structure then the second also satisfies the formula. Moshier and Rounds 1987 shows that no Kasper and Rounds logic with unrestricted classical implication is subsumption monotonic. Consequently, all Kasper and Rounds logics with implication have either nonclassical implication or, as in Carpenter logic, restricted classical implication. However, many HPSG 94 principles ....

Moshier, M. Drew, and William C. Rounds. 1987. A Logic for Partially Specified Data Structures. In Proceedings of the 14th ACM Symposium on Principles of Programming Languages, 156--167. Munich.

....a specific formal framework. For the most part, properties of classes of structures that are defined in a formal way like this are the provenance of Model Theory. It s not surprising, then, to find treatments of the meaning of such systems of constraints couched in terms of formal logic [KR86, MR87, KR90, GPC 88, Joh88, Smo89, DVS90, Car92, Kel93, RVS94] More recently, a number of people have noticed that, at least in some cases, extralogical mechanisms for combining constraints can be replaced by ordinary logical operations. See, for instance, Joh89, Sta92, Cor92, BGMV93, BMV94, ....

M. Drew Moshier and William C. Rounds. A logic for partially specified data structures. In ACM Symposium on the Principles of Programming Languages, 1987.

....In particular, to ensure each formula has a most general satisfier, a Kasper and Rounds DRAFT Towards Truth in HPSG 3 logic must be subsumption monotonic: if a first feature structure satisfies a formula and subsumes a second feature structure then the second also satisfies the formula. Moshier and Rounds 1987 shows that no Kasper and Rounds logic with unrestricted classical implication is subsumption monotonic. Consequently, all Kasper and Rounds logics with implication have either nonclassical implication or, as in Carpenter logic, restricted classical implication. However, many HPSG 94 principles ....

Moshier, M. Drew, and William C. Rounds. 1987. A Logic for Partially Specified Data Structures. In Proceedings of the 14th ACM Symposium on Principles of Programming Languages, 156--167. Munich.

.... 83, Kay84] Feature terms also have much in common with concept descriptions of terminological logics [BL84, Neb90, NS90] used in knowledge representation. At Kaci was the first to study such structures mathematically, which he called terms [AK86] Later, Kasper [KR86] Moshier and Rounds [MR87] as well as Smolka and At Kaci [SAK90] developed more powerful feature logics. In [Smo92] Smolka showed that the different feature term descriptions can be embedded into predicate logic. Feature terms are also very similar to context relations, a method for incremental and generic type inference ....

M. Drew Moshier and William C. Rounds. A logic for partially specified data structures. In Proc. 14th Annual ACM Symposium on Principles of Programming Languages, pages 156--167. ACM Press, January 1987.

....the kind presented in the body of this paper. One JL 26, 1990 Bird Klein Phonological events advantage of such a move is that it would provide a straightforward formal basis for adding logical negation and disjunction to our representations; see also Karttunen (1984) Kasper Rounds (1986) Moshier Rounds (1987) for general discussion of this issue. Another possible advantage of taking this step is that it would give us a formal framework in which to explore the proposal that the relation between phonology and phonetics is analogous to the distinction between syntax and (model theoretic) semantics. This ....

Moshier, M. D. and W. C. Rounds. (1987). A logic for partially specified data structures. ACM Symposium on the Principles of Programming Languages. Association for Computing Machinery.

....sequence d 0 d 1 d 2 : of elements of D. We prove that subsumption of acyclic TFSs is well founded, and show an example of general (cyclic) TFSs for which subsumption is not well founded. While these results are not surprising, and in fact might be deduced from works such as, e.g. (Moshier and Rounds, 1987) or (Shieber, 1992) they were not, to the best of our knowledge, spelled out explicitly before. Lemma 3.1 A TFS A is acyclic iff Pi(A) is finite. Proof: If A is cyclic, there exists a node q 2 Q and a non empty path ff that ffi(q; ff) q. Since q is accessible, let be the path from the root ....

Moshier, Drew M. and William C. Rounds. 1987. A logic for partially specified data structures.

....by the idea implicit in intuitionistic logic that a negative statement is one that can be positively refuted. This chapter is not the place to review these well known ideas, but this section is appropriate for mentioning the intuitionistic version of feature logic introduced by Moshier and Rounds [49], in fact to recapture the persistence property of Kasper Rounds while at the same time dealing with the problems mentioned in the section on three valued systems. The syntax of feature logic remains the same in this section; we have KasperRounds augmented with negation and implication (and the ....

M. A. Moshier and W. Rounds. A logic for partially specified data structures. In Proceedings of 14th ACM Symposium on Principles of Programming Languages, 1987.

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M.A. Moshier and W. C. Rounds. A logic for partially specified data structures. In Proceedings of the 14th ACM Symposium on Principles of Programming Languages,pages156--167, 1987.

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