Intermediate Aspects
This chapter builds on the basic concepts and syntax of LogiQL considered in the previous chapter and introduces some more advanced features of the language. Although the British monarchy remains the primary domain from which examples and exercises are constructed, we begin to introduce other,...
| Main Authors: | , |
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| Format: | Book Section |
| Language: | English |
| Published: |
Taylor & Francis Group
2015
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| Subjects: | |
| Online Access: | http://eprints.intimal.edu.my/329/ http://eprints.intimal.edu.my/329/1/8_ft.pdf |
| Summary: | This chapter builds on the basic concepts and syntax of LogiQL
considered
in the previous chapter and introduces some more
advanced features of the language. Although the British monarchy
remains the primary domain from which examples and exercises are constructed,
we begin to introduce other, more business-oriented domains to
demonstrate the breadth of applicability of LogiQL.
The first unit considers inverse-functional predicates, which are binary
predicates where the first argument is a function of the second argument.
The second unit discusses predicates that have more than two arguments
and also surveys the various kinds of numeric datatypes available in
LogiQL. The next unit covers some constraints that apply to two or more
predicate arguments. We then learn how to use subtyping, where a type is
contained in a larger type (e.g., Woman is a subtype of Person), as well as
some simple subset constraints. The following unit then examines recursion,
one of LogiQL’s most powerful features, and discusses constraints
that often apply to predicates used in recursive rules. The final unit introduces
two of LogiQL’s aggregation functions (count and total), useful
for computing properties of a set of facts in the database. The consolidation
exercise gives you an opportunity to test your mastery of the new
concepts and syntax considered in the chapter. |
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