Abs t rac t . In this paper we extend work of Treitel and Genesereth for calculating cost estimates for alternative proof methods of logic programs. We consider four methods: (1) forward chaining by semi-n~ive bottom-up evaluation, (2) goM-directed forward chaining by semi-n~ive bottom-up evaluation after Generalized Magic-Sets rewriting, (3) b~ckwaxd chaining by OLD resolution, and (4) memoing...

This article represents one of the contemporary trends in the application of the latest methods of information and communication technology for medicine through an expert system helps the doctor to diagnose some chest diseases which is important because of the frequent spread of chest diseases nowadays in addition to the overlap symptoms of these diseases, which is difficult to right diagnose b...

CLIPS cannot effectively perform sound and complete logical inference in most real-world contexts. The problem facing CLIPS is its lack of goal generation. Without automatic goal generation and maintenance, Forward chaining can only deduce all instances of a relationship. Backward chaining, which requires goal generation, allows deduction of only that subset of what is logically true which is a...

This study characterizes hinting strategies used by a human tutor to help students learn geometry theorem proving. Current tutoring systems for theorem proving provide hints that encourage (or force) the student to follow a fixed forward and/or backward chaining strategy. In order to find out if human tutors observed a similar constraint, a study was conducted with students proving geometry the...

This paper introduces first an expert system shell based on stratified forward chaining. The stratified forward chaining was proposed as a generalization for the inheritance networks with exception since it allows more than one antecedent in the premises part of a rule. Expert systems built with this tool are rule based and the user interface is web based. The practical use of this chaining is ...

Metacognitive skills have been commonly associated with preparation for future learning in deductive domains. Many researchers regarded strategy- and time-awareness as two metacognitive that address how when to use a problem-solving strategy, respectively. It was shown students who are both time-aware (StrTime) outperformed their nonStrTime peers across In this work, were trained on logic tutor...

We consider positive rules in which the conclusion may contain existentially quantified variables, which makes reasoning tasks (such as conjunctive query answering or entailment) undecidable. These rules, called ∀∃-rules, have the same logical form as tuple-generating dependencies in databases and as conceptual graph rules. The aim of this paper is to provide a clearer picture of the frontier b...

Structured derivations were introduced by Back and von Wright as an extension of the calculational proof style originally proposed by E.W. Dijkstra and his colleagues. Structured derivations added nested subderivations and inherited assumptions to the original calculational style. This paper introduces a further extension of the structured derivation format, and gives a precise syntax and seman...