arXiv subjects

Keehang Kwon

Publications and source records attributed to Keehang Kwon.

44 records · Page 3Linked to original sources

arXiv2013

Accomplishable Tasks in Knowledge Representation

Knowledge Representation (KR) is traditionally based on the logic of facts, expressed in boolean logic. However, facts about an agent can also be seen as a set of accomplished tasks by the agent. This paper proposes a new approach to KR: the notion of task logical KR based on Computability Logic. This notion allows the user to represent both accomplished tasks and accomplishable tasks by the agent. This notion allows us to build sophisticated KRs about many interesting agents, which have not been supported by previous logical languages.

cs.AI↗

arXiv2013

Expressing Algorithms As Concise As Possible via Computability Logic

This paper proposes a new approach to defining and expressing algorithms: the notion of {\it task logical} algorithms. This notion allows the user to define an algorithm for a task $T$ as a set of agents who can collectively perform $T$. This notion considerably simplifies the algorithm development process and can be seen as an integration of the sequential pseudocode and logical algorithms. This observation requires some changes to algorithm development process. We propose a two-step approach: the first step is to define an algorithm for a task $T$ via a set of agents that can collectively perform $T$. The second step is to translate these agents into (higher-order) computability logic.

cs.LO↗

arXiv2013

Towards Interactive Object-Oriented Programming

To represent interactive objects, we propose a choice-disjunctive declaration statement of the form S R where S;R are the (procedure or field) declaration statements within a class. This statement has the following semantics: request the user to choose one between S and R when an object of this class is created. This statement is useful for representing interactive objects that require interactions with the user.

cs.PL↗

arXiv2012

Improving Robustness via Disjunctive Statements in Imperative Programming

To deal with failures as simply as possible, we propose a new foun- dation for the core (untyped) C, which is based on a new logic called task logic or imperative logic. We then introduce a sequential-disjunctive statement of the form S : R. This statement has the following semantics: execute S and R sequentially. It is considered a success if at least one of S;R is a success. This statement is useful for dealing with inessential errors without explicitly catching them.

cs.PL↗

arXiv2012

Mutually Exclusive Rules in LogicWeb

LogicWeb has traditionally lacked devices for expressing mutually exclusive clauses. We address this limitation by adopting choice-conjunctive clauses of the form $D_0 \adc D_1$ where $D_0, D_1$ are Horn clauses and $\adc$ is a linear logic connective. Solving a goal $G$ using $D_0 \adc D_1$ -- $\prov(D_0 \adc D_1,G)$ -- has the following operational semantics: choose a successful one between $\prov(D_0,G)$ and $\prov(D_1,G)$. In other words, if $D_o$ is chosen in the course of solving $G$, then $D_1$ will be discarded and vice versa. Hence, the class of choice-conjunctive clauses precisely captures the notion of mutually exclusive clauses.

cs.LO↗

arXiv2010

A proof Procedure for Testing Membership in Regular Expressions

We propose an algorithm that test membership for regular expressions and show that the algorithm is correct. This algorithm is written in the style of a sequent proof system. The advantage of this algorithm over traditional ones is that the complex conversion process from regular expressions to finite automata is not needed. As a consequence, our algorithm is simple and extends easily to various extensions to regular expressions such as timed regular expressions or regular languages with the intersection.

cs.FL↗

arXiv2009

Algorithm as Defining Dynamic Systems

This paper proposes a new view to algorithms, Algorithms as defining dynamic systems. This view extends the traditional, deterministic view that an algorithm is a step by step procedure with nondeterminism. As a dynamic system can be designed by a set of its defining laws, it is also desirable to design an algorithm by a (possibly nondeterministic) set of defining laws. This observation requires some changes to algorithm development. We propose a two step approach, the first step is to design an algorithm via a set of defining laws of dynamic system. The second step is to translate these laws (written in a natural language) into a formal language such as linear logic.

cs.DS↗

arXiv1998

Scoping Constructs in Logic Programming: Implementation Problems and their Solution

The inclusion of universal quantification and a form of implication in goals in logic programming is considered. These additions provide a logical basis for scoping but they also raise new implementation problems. When universal and existential quantifiers are permitted to appear in mixed order in goals, the devices of logic variables and unification that are employed in solving existential goals must be modified to ensure that constraints arising out of the order of quantification are respected. Suitable modifications that are based on attaching numerical tags to constants and variables and on using these tags in unification are described. The resulting devices are amenable to an efficient implementation and can, in fact, be assimilated easily into the usual machinery of the Warren Abstract Machine (WAM). The provision of implications in goals results in the possibility of program clauses being added to the program for the purpose of solving specific subgoals. A naive scheme based on asserting and retracting program clauses does not suffice for implementing such additions for two reasons. First, it is necessary to also support the resurrection of an earlier existing program in the face of backtracking. Second, the possibility for implication goals to be surrounded by quantifiers requires a consideration of the parameterization of program clauses by bindings for their free variables. Devices for supporting these additional requirements are described as also is the integration of these devices into the WAM. Further extensions to the machine are outlined for handling higher-order additions to the language. The ideas presented here are relevant to the implementation of the higher-order logic programming language lambda Prolog.

cs.PL↗