Guo-Qiang Zhang

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We introduce a domain-theoretic foundation for disjunctive logic programming. This foundation is built on clausal logic, a representation of the Smyth powerdomain of any coherent algebraic dcpo. We establish the completeness of a resolution rule for inference in such a clausal logic; we introduce a natural declarative semantics and a fixed-point semantics(More)
In this paper we show that the Mastermind Satisfiability Problem (MSP) is NPcomplete. Mastermind is a popular game which can be turned into a logical puzzle called the Mastermind Satisfiability Problem in a similar spirit to the Minesweeper puzzle [5]. By proving that MSP is NP-complete, we reveal its intrinsic computational property that makes it(More)
This paper presents a Boolean-matrix based method to automata theory, with an application to the study of regularity-preserving functions. A new characterization of such functions is derived in terms of the property of ultimate periodicity with respect to powers of Boolean matrices. This characterization reveals the intrinsic algebraic nature of(More)
We introduce a framework for the study of formal contexts and their lattices induced by the additional structure of self-relations on top of the traditional incidence relation. The induced contexts use subsets as objects and attributes, hence the name power context and power concept. Six types of new incidence relations are introduced by taking into account(More)
Disjunctive systems are a representation of L-domains. They use sequents of the form X ` Y , with X nite and Y pairwise disjoint. We show that for any disjunctive system, its elements ordered by inclusion form an L-domain. On the other hand, via the notion of stable neighborhoods, every L-domain can be represented as a disjunctive system. More generally, we(More)
Entailment relations, originated from Scott, have been used for describing mathematical concepts constructively and for representing categories of domains. This paper gives an analysis of the freely generated frames from entailment relations. This way, we obtain completeness results under the unifying principle of the spatiality of coherence logic. In(More)
We present an innovative approach to information retrieval for domain-specific digital library collections. We use a combination of Formal Concept Analysis (FCA) and a notion of information anchors to facilitate information delivery to the end user. This approach (1) uses ranked objects in attribute concepts to facilitate topical queries for experts and(More)