DIGITAL.CSIChttps://digital.csic.esThe DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material.Sun, 24 Oct 2021 04:15:59 GMT2021-10-24T04:15:59Z5041- On the existence of free models in fuzzy universal Horn classeshttp://hdl.handle.net/10261/157527Title: On the existence of free models in fuzzy universal Horn classes
Authors: Costa, Vicent; Dellunde, Pilar
Abstract: This paper is a contribution to the study of the universal Horn fragment of predicate fuzzy logics, focusing on some relevant notions in logic programming. We introduce the notion of term structure associated to a set of formulas in the fuzzy context and we show the existence of free models in fuzzy universal Horn classes. We prove that every equality-free consistent universal Horn fuzzy theory has a Herbrand model. © 2016 Elsevier B.V.
Tue, 21 Nov 2017 13:35:49 GMThttp://hdl.handle.net/10261/1575272017-11-21T13:35:49Z
- Syntactic characterizations of classes of first-order structures in mathematical fuzzy logichttp://hdl.handle.net/10261/197511Title: Syntactic characterizations of classes of first-order structures in mathematical fuzzy logic
Authors: Badia, Guillermo; Costa, Vicent; Dellunde, Pilar; Noguera, Carles
Abstract: This paper is a contribution to graded model theory, in the context of mathematical fuzzy logic. We study characterizations of classes of graded structures in terms of the syntactic form of their first-order axiomatization. We focus on classes given by universal and universal–existential sentences. In particular, we prove two amalgamation results using the technique of diagrams in the setting of structures valued on a finite MTL-algebra, from which analogues of the Loś–Tarski and the Chang–Loś–Suszko preservation theorems follow.
Wed, 08 Jan 2020 12:49:31 GMThttp://hdl.handle.net/10261/1975112020-01-08T12:49:31Z
- Term Models of Horn Clauses over Rational Pavelka Predicate Logichttp://hdl.handle.net/10261/241124Title: Term Models of Horn Clauses over Rational Pavelka Predicate Logic
Authors: Costa, Vicent; Dellunde, Pilar
Abstract: [EN]This paper is a contribution to the study of the
universal Horn fragment of predicate fuzzy logics, focusing
on the proof of the existence of free models of theories of
Horn clauses over Rational Pavelka predicate logic. We define
the notion of a term structure associated to every consistent
theory T over Rational Pavelka predicate logic and we prove
that the term models of T are free on the class of all models
of T. Finally, it is shown that if T is a set of Horn clauses, the
term structure associated to T is a model of T.
Wed, 19 May 2021 08:22:11 GMThttp://hdl.handle.net/10261/2411242021-05-19T08:22:11Z
- On Free Models for Horn Clauses over Predicate Fuzzy Logicshttp://hdl.handle.net/10261/248324Title: On Free Models for Horn Clauses over Predicate Fuzzy Logics
Authors: Costa, Vicent; Dellunde, Pilar
Abstract: [EN]This paper is a preliminary study of the universal Horn fragment of Predicate Fuzzy Logics. We work in languages with a binary predicate symbol that is interpreted as a similarity. Using this similarity relation we define a term structure associated to a theory, and we prove that it is a free structure on the class of reduced models of the theory. Finally, we show that the substructure generated by the set of ground terms is a model of all universal Horn sentences that are logical consequences of the theory.
Wed, 18 Aug 2021 13:15:30 GMThttp://hdl.handle.net/10261/2483242021-08-18T13:15:30Z