## A Feature Logic with Subsorts (1992)

Venue: | LILOG Report 33, IWBS, IBM Deutschland |

Citations: | 74 - 4 self |

### BibTeX

@TECHREPORT{Smolka92afeature,

author = {Gert Smolka},

title = {A Feature Logic with Subsorts},

institution = {LILOG Report 33, IWBS, IBM Deutschland},

year = {1992}

}

### Years of Citing Articles

### OpenURL

### Abstract

This paper presents a set description logic with subsorts, feature selection (the inverse of unary function application), agreement, intersection, union and complement. We define a model theoretic open world semantics and show that sorted feature structures constitute a canonical model, that is, without loss of generality subsumption and consistency of set descriptions can be considered with respect to feature structures only. We show that deciding consistency of set descriptions is an NP-complete problem. To appear in: J. Wedekind and C. Rohrer (eds.), Unification in Grammar. The MIT Press, 1992 This text is a minor revision of LILOG Report 33, May 1988, IBM Deutschland, IWBS, Postfach 800880, 7000 Stuttgart 80, Germany. The research reported here has been done while the author was with IBM Deutschland. The author's article [23] is a more recent work on feature logics. 1 1 Introduction This paper presents a set description logic that generalizes and integrates formalisms...

### Citations

812 | The Semantics of Constraint Logic Programs
- Jaffar, Maher, et al.
- 1998
(Show Context)
Citation Context ... of rational records. Mukai also realizes that CIL is an instance of constraint logic programming, an approach that originated with Colmerauer's [5] Prolog-II and was generalized by Jaffar and Lassez =-=[8]-=-. Recent research [7] investigates logic programming based on feature logic and open world semantics. The presence of feature term unions (disjunctions) can diminish the need for backtracking and feat... |

622 | An overview of the KL-ONE knowledge representation system
- Brachman, Schmolze
- 1985
(Show Context)
Citation Context ...ut the special forms needed to formulate the above assumptions about features are weak enough to preserve decidability. Feature logic is closely related to the knowledge representation language KLONE =-=[4, 15]-=-. Both formalisms enjoy an open worlds semantics, are based on a classification scheme (the primitive concepts of KL-ONE are sorts) and have set denoting terms (called concept terms in KL-ONE). KL-ONE... |

555 | LexicalFunctional Grammar: a formal system for grammatical representation
- Kaplan, Bresnan
- 1982
(Show Context)
Citation Context ...terms as directly denoting sets of linguistic objects and there is still no need for making precise what linguistic objects are. Incidentally, this view reconciles the positions of Kaplan and Bresnan =-=[10]-=- and Kay [14]: while Kaplan and Bresnan argue for a strict distinction between feature descriptions and feature structures, Kay insists that there are only feature descriptions (which he calls feature... |

453 | An Introduction to Unification-based Approaches to Grammar - Shieber - 1986 |

179 |
Information-based Syntax and Semantics. Volume I: Fundamentals
- Pollard, Sag
- 1987
(Show Context)
Citation Context ...istency problem remains NP-hard even if only feature terms without complements and agreements are considered. Several variants of feature descriptions are being used in computational linguistics (see =-=[22, 19, 20]-=- for introductory expositions). In unification grammars [10, 14], unification of feature descriptions is the basic operational mechanism for parsing and generating natural language. A unification meth... |

153 |
LOGIN: A Logic Programming Language with Built-In Inheritance
- Ait-Kaci, Nasr
- 1986
(Show Context)
Citation Context ...ws the duality of the two approaches under the given initial algebra semantics. Furthermore, we present a unification algorithm that combines order-sorted unification [27, 28] with /-term unification =-=[1, 3]-=-. The paper is organized as follows. Section 2 formalizes signatures, interpretations and feature terms and shows that every feature term can be rewritten as a union of simple feature terms. Section 3... |

133 | A logical semantics for feature structures - Kasper, Rounds - 1986 |

128 |
Expressiveness and tractability in knowledge representation and reasoning
- Levesque, Brachman
- 1987
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Citation Context ...ut the special forms needed to formulate the above assumptions about features are weak enough to preserve decidability. Feature logic is closely related to the knowledge representation language KLONE =-=[4, 15]-=-. Both formalisms enjoy an open worlds semantics, are based on a classification scheme (the primitive concepts of KL-ONE are sorts) and have set denoting terms (called concept terms in KL-ONE). KL-ONE... |

111 |
Attribute-Value Logic and the Theory of Grammar, volume 16 of CSLI Lecture Notes
- Johnson
- 1988
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Citation Context ...ics. 1 1 Introduction This paper presents a set description logic that generalizes and integrates formalisms that have been developed for knowledge representation [1, 2] and computational linguistics =-=[13, 21, 11, 9]-=-. The logic comes with an open world model theoretic semantics, where admissible worlds can be required to satisfy a classification scheme postulated by means of a sort lattice. The logic supports the... |

101 |
Equations and Inequations on Finite and Infinite Trees
- Colmerauer
- 1984
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Citation Context ...es a declarative semantics for CIL using a fixed domain of rational records. Mukai also realizes that CIL is an instance of constraint logic programming, an approach that originated with Colmerauer's =-=[5]-=- Prolog-II and was generalized by Jaffar and Lassez [8]. Recent research [7] investigates logic programming based on feature logic and open world semantics. The presence of feature term unions (disjun... |

88 | Feature constraint logics for unification grammars
- Smolka
- 1992
(Show Context)
Citation Context ...LILOG Report 33, May 1988, IBM Deutschland, IWBS, Postfach 800880, 7000 Stuttgart 80, Germany. The research reported here has been done while the author was with IBM Deutschland. The author's article =-=[23]-=- is a more recent work on feature logics. 1 1 Introduction This paper presents a set description logic that generalizes and integrates formalisms that have been developed for knowledge representation ... |

84 | Definite relations over constraint languages
- Hohfeld, Smolka
- 1988
(Show Context)
Citation Context ... Mukai also realizes that CIL is an instance of constraint logic programming, an approach that originated with Colmerauer's [5] Prolog-II and was generalized by Jaffar and Lassez [8]. Recent research =-=[7]-=- investigates logic programming based on feature logic and open world semantics. The presence of feature term unions (disjunctions) can diminish the need for backtracking and feature term complements ... |

72 |
Parsing in functional unification grammar
- Kay
- 1986
(Show Context)
Citation Context ...omplements and agreements are considered. Several variants of feature descriptions are being used in computational linguistics (see [22, 19, 20] for introductory expositions). In unification grammars =-=[10, 14]-=-, unification of feature descriptions is the basic operational mechanism for parsing and generating natural language. A unification method for feature descriptions consists of a normal form that exhib... |

68 |
A complete logical calculus for record structures representing linguistic information
- Rounds, Kasper
- 1986
(Show Context)
Citation Context ...ics. 1 1 Introduction This paper presents a set description logic that generalizes and integrates formalisms that have been developed for knowledge representation [1, 2] and computational linguistics =-=[13, 21, 11, 9]-=-. The logic comes with an open world model theoretic semantics, where admissible worlds can be required to satisfy a classification scheme postulated by means of a sort lattice. The logic supports the... |

57 | An algebraic semantics approach to the effective resolution of type equations - Aı̈t-Kaci - 1986 |

50 |
Order-sorted equational computation
- SMOLKA, Nu’rr, et al.
- 1989
(Show Context)
Citation Context ...stance, for the definition of subsumption). In [24] we give an initial algebra semantics (closed world) for feature descriptions drawn over inheritance hierarchies using order-sorted equational logic =-=[25]-=-. This approach accommodates data types whose elements are described by features as well as data types whose elements are described by constructors and shows the duality of the two approaches under th... |

48 |
A Lattice-Theoretic Approach to Computation Based on a Calculus of Partially-Ordered Type Structures
- Ait-Kaci
- 1984
(Show Context)
Citation Context ... is a more recent work on feature logics. 1 1 Introduction This paper presents a set description logic that generalizes and integrates formalisms that have been developed for knowledge representation =-=[1, 2]-=- and computational linguistics [13, 21, 11, 9]. The logic comes with an open world model theoretic semantics, where admissible worlds can be required to satisfy a classification scheme postulated by m... |

44 | The semantics of grammar formalisms seen as computer languages
- Pereira, Shieber
- 1984
(Show Context)
Citation Context ...xjff(x) : = z; z: Ag and yjff(y) : = z; z: Ag are distinct if the root variables x and y are distinct. The records outlined in Section 1 do not have this redundancy. Incidentally, Pereira and Shieber =-=[18]-=- formalize feature structures as possibly infinite records. In general, record structures don't constitute a canonical interpretation. To see this, consider a signature that has one singleton A, two f... |

43 |
Uni method for disjunctive feature descriptions
- Kasper
- 1987
(Show Context)
Citation Context ...n Johnson's and Rounds and Kasper's formalisms. However, feature terms with variables allow for exponentially more succinct descriptions, a fact that is important for efficient unification algorithms =-=[12, 6]-=-. We will also introduce quantification for feature terms with variables and present a quantifier elimination algorithm that computes for every feature term an equivalent quantifier-free feature term,... |

36 |
A logic for partially specified data structures
- Moshier, Rounds
- 1987
(Show Context)
Citation Context ...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, w... |

29 |
Inheritance hierarchies: Semantics and unification
- Smolka, Aı̈t-Kaci
- 1990
(Show Context)
Citation Context ...l theoretic semantics for his formalism that is equivalent to the semantics presented in this paper, but he doesn't exploit this idea any further (for instance, for the definition of subsumption). In =-=[24]-=- we give an initial algebra semantics (closed world) for feature descriptions drawn over inheritance hierarchies using order-sorted equational logic [25]. This approach accommodates data types whose e... |

29 |
A mechanical solution of schubert’s steamroller by many-sorted resolution
- Walther
- 1984
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Citation Context ...described by constructors and shows the duality of the two approaches under the given initial algebra semantics. Furthermore, we present a unification algorithm that combines order-sorted unification =-=[27, 28]-=- with /-term unification [1, 3]. The paper is organized as follows. Section 2 formalizes signatures, interpretations and feature terms and shows that every feature term can be rewritten as a union of ... |

25 | Uni of disjunctive feature descriptions
- Eisele, Dorre
- 1988
(Show Context)
Citation Context ...n Johnson's and Rounds and Kasper's formalisms. However, feature terms with variables allow for exponentially more succinct descriptions, a fact that is important for efficient unification algorithms =-=[12, 6]-=-. We will also introduce quantification for feature terms with variables and present a quantifier elimination algorithm that computes for every feature term an equivalent quantifier-free feature term,... |

24 |
Feature structures: a logical theory with applications to language analysis
- Kasper
- 1987
(Show Context)
Citation Context ...ics. 1 1 Introduction This paper presents a set description logic that generalizes and integrates formalisms that have been developed for knowledge representation [1, 2] and computational linguistics =-=[13, 21, 11, 9]-=-. The logic comes with an open world model theoretic semantics, where admissible worlds can be required to satisfy a classification scheme postulated by means of a sort lattice. The logic supports the... |

23 |
Grammars and logics of partial information
- Pereira
- 1987
(Show Context)
Citation Context ...istency problem remains NP-hard even if only feature terms without complements and agreements are considered. Several variants of feature descriptions are being used in computational linguistics (see =-=[22, 19, 20]-=- for introductory expositions). In unification grammars [10, 14], unification of feature descriptions is the basic operational mechanism for parsing and generating natural language. A unification meth... |

22 |
Many-sorted unification
- Walther
- 1988
(Show Context)
Citation Context ...described by constructors and shows the duality of the two approaches under the given initial algebra semantics. Furthermore, we present a unification algorithm that combines order-sorted unification =-=[27, 28]-=- with /-term unification [1, 3]. The paper is organized as follows. Section 2 formalizes signatures, interpretations and feature terms and shows that every feature term can be rewritten as a union of ... |

5 |
Anadic Tuples in Prolog
- Mukai
- 1987
(Show Context)
Citation Context ...GIN [3], which pioneered this approach, feature terms (without singletons, unions and complements) take the place of ordinary terms and feature unification replaces ordinary term unification. Mukai's =-=[17]-=- language CIL is similar but uses constants instead of sorts. While LOGIN is presented without a declarative semantics, Mukai defines a declarative semantics for CIL using a fixed domain of rational r... |

3 |
From Feature Bundles to Abstract Data Types: New Directions in the Representation and Processing of Linguistic Knowledge
- Uszkoreit
- 1988
(Show Context)
Citation Context ... the technical sections of the paper. Acknowledgement. Gunther Gorz and Hans Uszkoreit were patient enough to give me some idea of what is going on in computational linguistics. Hans Uszkoreit's STUF =-=[26]-=-, which is used as the central representation formalism in the LILOG project at IBM, provided me with the challenge to capture some of it in logic. From Mark Johnson's thesis I learned that complement... |