Horn Theories Research Articles

The Logical Difference Between Propositional Horn Theories

The logical difference between knowledge bases is an important issue for the dynamic update of knowledge base. Computing the logical difference for knowledge bases is intractable in general, and its result is not necessarily category in the sense that the logical difference between two theories in a class is possibly not in the same class any more. This paper proves that computing logical difference between Horn theories is easier than that of CNF theories, and its result is still Horn expressible, though some deciding problems relating to logical difference are still intractable for Horn theories. A preliminary experiment illustrates an interesting phenomenon for the size of logical differences.

IMPLEMENTASI PROGRAM PARIWISATA DALAM MENINGKATKAN DESTINASI WISATA DI KABUPATEN JOMBANG

Tourism is the potential of each region, with the optimal management of the tourism sector is able to improve the economic growth of surrounding communities. In response to the problem of managing the tourism sector, not only the government that is responsible, but the role of private and public sectors is needed which is run according to the tourism program in Jombang. The tourism problem Jombang much frequented by foreign tourism and domestic tourist and increase from year but no significant impact on revenue. This study uses data collection techniques interviews and documentation. Technical analysis of the data used include qualitative data analysis. The result of this study refers to the theory of Van Meter and Van Horn as a confirmation of the theory. This study found that tourism program Jombang is not optimal, the number of tourist who visit do not have an impact on increasing revenue for local government. It was also found not optimal implementation of tourism programs implemented. Tourism policy by applying the model of information system integrated tourism (integrated tourism/IT) can be synergized and integrated toursm development program that is ideal in these destinations and the socialization of program / tourism activities be intensified and evenly to the surrounding community to express their aspirations so that this cooperation can goes well and provide benefits to all and teint parties. eg travel agents, transportation, hotels, catering, tour operators, tour operators, tourist attraction and souvenir shop, where everything is together teintergrasi it will have an impact on increase in tourist destinations and revenue.

“Implementasi Peraturan Daerah (PERDA) Nomor 1 Tahun 2015 tentang Perlindungan dan Pemenuhan Hak Penyandang Disabilitas di SLB-B Kabupaten Wonosobo”

The implementation of education for disabilities persons is carried out through special education and inclusion with specific curricula and learning processes and learning places, but the role of the Wonosobo regency government tackles this problem less than optimal. This study aims to describe how the implementation of Regional Regulation Number 1 of 2015 on the Protection and Fulfillment of the Rights of Disabilities Persons in extraordinary school of Wonosobo Regency, and to identify the supporting and inhibiting aspects of the implementation of the Regional Regulation. The theory used is the implementation model of George Edward III, Mazmanian and Sabatier, Mazmanian and Sabatier, as well as Meter and Horn theory. The research studied using descriptive research approach. Data collection techniques used in the form of interviews, obervasi and documentation, with qualitative descriptive data analysis. The results show that in general the government, school and community institutions have the same perception toward the principle, purpose and purpose of the law. Protection of persons with disabilities has not fully covered all types of persons with disabilities. Supporting the success of this policy is the environmental aspect with the high level of community support, the policy implementation aspect with the similarity of interests between the government and the community, the support of resources, and the good compliance and responsiveness of the implementers, and the characteristic aspects of the implementing agency with positive responses to policies and commitments the high of the executor. While inhibiting the success of the policy is the communication aspect by the local government and the communication from the community where many people with disability are shut down, the information about the existence of disabled people, and the environmental stagnant in the form of socioeconomic condition of the society which is low. The recommendation of the researcher is the need for better socialization by the government, as well as the effort to establish for Public Extraordinary School of Wonosobo Regency, so that children with disability can be accommodated in special schools that are designated for children with disabilities.

Merging in the Horn Fragment

Belief merging is a central operation within the field of belief change and addresses the problem of combining multiple, possibly mutually inconsistent knowledge bases into a single, consistent one. A current research trend in belief change is concerned with representation theorems tailored to fragments of logic, in particular Horn logic. Hereby, the goal is to guarantee that the result of the change operations stays within the fragment under consideration. While several such results have been obtained for Horn revision and Horn contraction, merging of Horn theories has been neglected so far. In this article, we provide a novel representation theorem for Horn merging by strengthening the standard merging postulates. Moreover, we present concrete Horn merging operators satisfying all postulates.

Permutation Groups in Categorical Additive Horn Theories

Permutation Groups in Categorical Additive Horn Theories

IMPLEMENTASI KEBIJAKAN PEMERINTAH KOTA CIREBON DALAM MENINGKATKAN KETERTIBAN PEDAGANG KAKI LIMA (Studi Kasus di Jl. Siliwangi Kota Cirebon)

ABSTRACT Street Vendors is a very complicated thing to ensure order. This became the basic tasks of municipal government in particular Cirebon Civil Service Police Unit to regulate street vendors, economic needs urgent that makes the street vendors sell on the road or on the sidewalk which should be forbidden by the local government area. The problem that arises if the implementation of policies regulating street vendors in the city of Cirebon can be increased in accordance with local regulations No. 9 of 2003 on Public Order policy on public order policy on public order by the local governments aimed so the vendors are supposed to walk not violate so as to create (Health, Beauty, and Order)The method used is qualitative research informant with the chairman of the peace and public order agencies Civil Service Police Unit Cirebon city and street vendors on the sidewalks and on the road in Jalan Siliwangi Cirebon City. Techniques of data collection using interviews, observation, data analysis, and data validity.Research results show that Control Policy Implementation street vendors in the city of Cirebon (status cases Jl. Siliwangi) is not optimal it is still a lot of problems including lack of regulatory policy on regulating local street vendors. Theories are taken using the theory of Van Meter and Van Horn include the size and purpose of the policy, resources, characteristics of the implementing agencies, communication between relevant organizations and implementing activities, social environment, political economy which is still unresolved due to the limited quality and quantity of the resources, the means, and infrastructure support order is not optimal.

A representation of recursively enumerable sets through Horn formulas in higher recursion theory

We extend a classical result in ordinary recursion theory to higher recursion theory, namely that every recursively enumerable set can be represented in any model \(\mathfrak {A}\) by some Horn theory, where \(\mathfrak {A}\) can be any model of a higher recursion theory, like primitive set recursion, \(\alpha \)-recursion, or \(\beta \)-recursion. We also prove that, under suitable conditions, a set defined through a Horn theory in a set \(\mathfrak {A}\) is recursively enumerable in models of the above mentioned recursion theories.

Implementasi Perda Nomor 6 Tahun 2011 Tentang Pajak Reklame Di Kota Semarang

Advertisement tax is a levies that local districts / cities on the implementation of the billboard. Advertising Tax convening aims to help improve the original income in order to carry out the development and care of the household own areas. In fact in the implementation of policy implementation have not been fully able to bring results in line with the target set. The focus of this research is the Implementation Regulations of Law 6 of 2011 about the advertisement tax in Semarang as the locus of research. This study uses theory implementation proposed by George Edward III, Meter and Horn theory and the theory of Grindle. This type of research is explanatory research that examines the influence between variables with hypothesis testing. The unit of analysis is the implementing agency personnel policy the implementation Regulations of Law 6 of 2011 about the advertisement tax in Semarang related (Employee field of local taxes). A representative sample use Proportional Random Sampling technique by taking 30 respondents. Statistical testing to measure the accuracy of instruments questions using validity and reliability test. hypothesis testing using the formula Kendall Rank Correlation Coefficient with Z Significance Tests with SPSS method and coefficient of determination.. The research proves that there is a positive and significant relationship between attitudes to the implementation Regulations of Law 6 of 2011 about the advertisement tax in Semarang by 11.4% relationship. There is a positive and significant relationship between communication with the implementation Regulations of Law 6 of 2011 about the advertisement tax in Semarang by 16.4% relationship. These results indicate that the hypothesis proposed in this study received. Based on the research, in order to achieve the successful Implementation Regulation 6 of 2011 about the advertisement tax, DPKAD Semarang need to conduct more intensive training to officers and providing extension or a more intensive socialization to taxpayers.

Learning definite Horn formulas from closure queries

A definite Horn theory is a set of n-dimensional Boolean vectors whose characteristic function is expressible as a definite Horn formula, that is, as conjunction of definite Horn clauses. The class of definite Horn theories is known to be learnable under different query learning settings, such as learning from membership and equivalence queries or learning from entailment. We propose yet a different type of query: the closure query. Closure queries are a natural extension of membership queries and also a variant, appropriate in the context of definite Horn formulas, of the so-called correction queries. We present an algorithm that learns conjunctions of definite Horn clauses in polynomial time, using closure and equivalence queries, and show how it relates to the canonical Guigues–Duquenne basis for implicational systems. We also show how the different query models mentioned relate to each other by either showing full-fledged reductions by means of query simulation (where possible), or by showing their connections in the context of particular algorithms that use them for learning definite Horn formulas.

Scalar implicature: a Saussurean system-based approach

Scalar implicature is a cutting-edge issue in linguistic pragmatics. The study is intended to argue that, within Saussure's thought of language as a system, scalar implicature is manifested as the system-based meaning, i.e., it is generated by the language system. It maintains that the notion of “scalar implicature” as one type of “associative implicature” should be integrated into the coherent theoretical model formulated in this study, thereby also rescuing Horn's theory on scales.

On the Computational Feasibility of Abductive Diagnosis for Practical Applications

Increasing complexity of physical systems demands an accurate fault localization in order to reduce maintenance costs. Model-based diagnosis has been proposed as an AI-based method to derive root causes from a system model and observable anomalies. Though relying on a strong theoretical background, practical applications of model-based diagnosis are often prevented by the initial modeling effort and complexity of diagnosis algorithms. In this paper, we focus on both aspects and present an approach that converts the fault information available in practice into propositional Horn logic sentences to be used in abductive diagnosis. It is well known that abductive diagnosis based on propositional Horn theories has exponential complexity in general. However, in our case the obtained logical sentences belong to a subset of propositional Horn logic that is tractable, namely definite Horn theories. In particular, we show that the abduction problem in case of the obtained models can be solved in polynomial time. We present empirical results obtained using real world examples and a parametrizable artificial example class. The data indicate that the proposed approach is feasible for practical applications.

Belief revision in Horn theories

This paper investigates belief revision where the underlying logic is that governing Horn clauses. We show that classical (AGM) belief revision doesn't immediately generalise to the Horn case. In particular, a standard construction based on a total preorder over possible worlds may violate the accepted (AGM) postulates. Conversely, in the obvious extension to the AGM approach, Horn revision functions are not captured by total preorders over possible worlds. We address these difficulties by introducing two modifications to the AGM approach. First, the semantic construction is restricted to “well behaved” orderings, what we call Horn compliant orderings. Second, the revision postulates are augmented by an additional postulate. Both restrictions are redundant in the AGM approach, but not in the Horn case. In a representation result we show that the class of revision functions captured by Horn compliant total preorders over possible worlds is precisely that given by the (extended) set of Horn revision postulates. Further, we show that Horn revision is compatible with work in iterated revision and work concerning relevance in revision. We also consider specific revision operators. Arguably this work is interesting for several reasons. It extends AGM revision to inferentially-weaker Horn theories; hence it sheds light on the theoretical underpinnings of belief change, as well as generalising the AGM paradigm. Thus, this work is relevant to revision in areas that employ Horn clauses, such as deductive databases and logic programming, as well as areas in which inference is weaker than classical logic, such as in description logic.

The Horn theory of Boole's partial algebras

AbstractThis paper augments Hailperin's substantial efforts (1976/1986) to place Boole's algebra of logic on a solid footing. Namely Horn sentences are used to give a modern formulation of the principle that Boole adopted in 1854 as the foundation for his algebra of logic—we call this principle The Rule of 0 and 1.

Deductive inference for the interiors and exteriors of horn theories

In this article, we investigate deductive inference for interiors and exteriors of Horn knowledge bases, where interiors and exteriors were introduced by Makino and Ibaraki [1996] to study stability properties of knowledge bases. We present a linear time algorithm for deduction for interiors and show that deduction is coNP-complete for exteriors. Under model-based representation, we show that the deduction problem for interiors is NP-complete while the one for exteriors is coNP-complete. As for Horn envelopes of exteriors, we show that it is linearly solvable under model-based representation, while it is coNP-complete under formula-based representation. We also discuss polynomially solvable cases for all the intractable problems.

Categorical Horn theories and modules

We study connection between categorical Horn theories and modules. We show that each function enrichment of any abelian group to a primitive normal structure is primitively equivalent to some module. We give a description for the categorical Horn classes of modules. We propose some sufficient conditions for a categorical Horn theory to be primitively equivalent to a theory of modules. In particular, such are the categorical Horn theories of enrichments of abelian groups with the conditions of primitive rank ≥ 3 and the absence of predicate symbols of arity ≤ 3 in the language.

Recursion principles for syntax with bindings and substitution

We characterize the data type of terms with bindings, freshness and substitution, as an initial model in a suitable Horn theory. This characterization yields a convenient recursive definition principle, which we have formalized in Isabelle/HOL and employed in a series of case studies taken from the λ-calculus literature.

Construction and learnability of canonical Horn formulas

We describe an alternative construction of an existing canonical representation for definite Horn theories, the Guigues-Duquenne basis (or GD basis), which minimizes a natural notion of implicational size. We extend the canonical representation to general Horn, by providing a reduction from definite to general Horn CNF. Using these tools, we provide a new, simpler validation of the classic Horn query learning algorithm of Angluin, Frazier, and Pitt, and we prove that this algorithm always outputs the GD basis regardless of the counterexamples it receives.

On quasi-varieties of multiple valued logic models

We extend the concept of quasi-variety of first-order models from classical logic to multiple valued logic (MVL) and study the relationship between quasi-varieties and existence of initial models in MVL. We define a concept of ‘Horn sentence’ in MVL and based upon our study of quasi-varieties of MVL models we derive the existence of initial models for MVL ‘Horn theories’. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

On systems of equations over free products of groups

Using an analogue of the Makanin–Razborov diagrams, we give a description of the solution set of systems of equations over an equationally Noetherian free product of groups G. Equivalently, we give a parametrisation of the set Hom ( H , G ) of all homomorphisms from a finitely generated group H to G. Furthermore, we show that every algebraic set over G can be decomposed as a union of finitely many images of algebraic sets of NTQ systems. If the universal Horn theory of G (the theory of quasi-identities) is decidable, then our constructions are effective.

Categorical horn classes. 2

We come up with a quite efficient characterization of uncountably categorical Horn classes, which, in particular, implies that the classes in question are model complete. It is also worth mentioning the following results: quantifier elimination down to primitive formulas, a description of groups interpretable in models of categorical Horn theories, and a characterization of groups interpretable in models of almost strongly minimal Horn theories.