The document discusses knowledge representation systems (KRS) and how they are used to represent knowledge in a symbolic form for computer processing. It provides examples of KRS tables and defines key concepts such as attributes, objects, equivalence relations, and discernibility matrices. Discernibility matrices are used to analyze the significance of attributes and determine attribute reducts.

1. Knowledge Representation Chapter 5

5. 2.Examples Table 1 Objects in the information System are U1,…,U2. Attributes are Headache, Muscle pain, Temp, Flu

6. [ Table 2 ] : Digits display unit in a calculator assumed to represent a characterization of “hand written” digits 1 1 0 1 1 1 1 9 1 1 1 1 1 1 1 8 0 0 0 0 1 1 1 7 1 1 1 1 1 0 1 6 1 1 0 1 1 0 1 5 1 1 0 0 1 1 0 4 1 0 0 1 1 1 1 3 1 0 1 1 0 1 1 2 0 0 0 0 1 1 0 1 0 1 1 1 1 1 1 0 G f e d c b a U a b c d e f g Objects in the information System are 1,…,9 Attributes are a, b, c, d, e, f, g

16. Example Table 1 Knowledge Representation System U a b c d 1 0 1 2 0 2 1 2 0 2 3 1 0 1 0 4 2 1 0 1 5 1 1 0 2

17. Table 2 Discernibility Matrix 1 5 a,d b,c,d b a,c,d 5 a,b,c,d a,b,d a,c,d 4 b,c,d a,b,c 3 a,b,c,d 2 4 3 2 1

18. Table 3 CORE reducts : {a, b} {d, b}