1. Reasoning Systems For Categories By Franklyn O

2. Reasoning Systems For Categories Categories are the primary building blocks of any large-scale knowledge representation scheme. Categories are the primary building blocks of any large-scale knowledge representation scheme. This topic describes systems specially designed for organizing and reasoning with category. This topic describes systems specially designed for organizing and reasoning with category. There are two types of Reasoning Systems There are two types of Reasoning Systems Semantic networks and description logic. Semantic networks and description logic.

3. Types of Reasoning Systems Semantic networks. Semantic networks provides graphical aids for visualizing a knowledge base in patterns of interconnected nodes and arcs. Semantic networks provides graphical aids for visualizing a knowledge base in patterns of interconnected nodes and arcs. It has an efficient algorithms for inferring of and object on the basis of its category membership. It has an efficient algorithms for inferring of and object on the basis of its category membership. In 1909 Charles Peirce proposed a graphical notation of nodes and arcs called existential graphs that is a visual notation for logical expressions In 1909 Charles Peirce proposed a graphical notation of nodes and arcs called existential graphs that is a visual notation for logical expressions

4. Semantic networks. A typical graphical notation displays objects or categories names in oval or boxes and connects them with labeled arcs. A typical graphical notation displays objects or categories names in oval or boxes and connects them with labeled arcs. For example a MemberOf link between Mary and female persons corresponds to the logical assertion Mary E (element) of female person. For example a MemberOf link between Mary and female persons corresponds to the logical assertion Mary E (element) of female person. We can connect categories using SubsetOf of links We can connect categories using SubsetOf of links A single box used to assert properties of every member of a category. A single box used to assert properties of every member of a category.

5. Semantic networks Semantic network notation makes it very convenient to perform inheritance reasoning. Semantic network notation makes it very convenient to perform inheritance reasoning. For example by virtue of being a person marry inherits the property of having two legs. For example by virtue of being a person marry inherits the property of having two legs. The simplicity and efficiency of this inference mechanism, compared with logical theorem has been one of the main attractions of semantic networks. The simplicity and efficiency of this inference mechanism, compared with logical theorem has been one of the main attractions of semantic networks. Inheritance becomes complicated when an object belong to more than one category Inheritance becomes complicated when an object belong to more than one category And also when a category can be a subset of more than one other category which is called multiple inheritance. And also when a category can be a subset of more than one other category which is called multiple inheritance.

6. Semantic networks multiple inheritance can cause the algorithm to find two or more conflicting values answering a query. multiple inheritance can cause the algorithm to find two or more conflicting values answering a query. For this reason multiple inheritance is banned in some object oriented programming like Java. For this reason multiple inheritance is banned in some object oriented programming like Java. Another form of inference is the use of inverse links. Another form of inference is the use of inverse links. For example HasSister is the inverse of SisterOf. For example HasSister is the inverse of SisterOf. Its ok to have inverse links as long as they are made into objects in their own right( Its ok to have inverse links as long as they are made into objects in their own right(

7. Semantic networks Semantic network provide direct indexing only for objects, categories and the links emanating from them Semantic network provide direct indexing only for objects, categories and the links emanating from them The drawback is that links between bubbles represent only one binary relation. The drawback is that links between bubbles represent only one binary relation.

8. Description logics They are logics notations that are designed to make it easier to describe definition and properties of categories. They are logics notations that are designed to make it easier to describe definition and properties of categories. It evolved from semantic network It evolved from semantic network The principal inference task for description logic are checking if one category is a subset of another by comparing their definition. The principal inference task for description logic are checking if one category is a subset of another by comparing their definition. By cheecking whether the membership criteria are logically certifiable. By cheecking whether the membership criteria are logically certifiable.

9. Description logics CLASSIC language is a typical description logic CLASSIC language is a typical description logic Any CLASSIC can be written in First Order Logic Any CLASSIC can be written in First Order Logic Description logics emphasis on tractability of inference Description logics emphasis on tractability of inference Hard problems cannot be stated or require large descrptions. Hard problems cannot be stated or require large descrptions.

10. ANY QUESTIONS ANY QUESTIONS