DL

Question 1

what 2 elements make up the description logic KB?

Answer 1

description logic KB:

1. TBOX - terminology
2. ABOX - assertions about individuals

Question 2

which 2 relationships between concepts are used in the TBOX?

Answer 2

TBOX

1. concept inclusion
2. concept equivalence

Question 3

which 2 types of assertional axioms are used in the ABOX?

Answer 3

ABOX

1. concept assertions - individual a is an instance of class C
2. role assertions - individual a is related to individual b through role r

Question 4

what is the tableau algorithm?

how does it work?

Answer 4

tableau algorithm is a refutation proof system
> perform a search through the tree of possible models of the input until it succeeds (=delivers proof) iff the input is inconsistent (=there is no model)

Question 5

which strategy can be used for all ALC reasoning task?

Answer 5

all ALC reasoning taks can be turned into a task of finding a model of the ABOX and TBOX

Question 6

what can we always do when the tableau algorithm terminates and the tableau is open?

Answer 6

costruct a canonical model of the input