1. CSE4/563: Knowledge Representation Recitation November 8, 2010
“Artificial intelligence is based on the assumption that the mind can be described as some kind of formal system manipulating symbols that stand for things in the world. Thus it doesn't matter what the brain is made of, or what it uses for tokens in the great game of thinking. Using an equivalent set of tokens and rules, we can do thinking with a digital computer, just as we can play chess using cups, salt and pepper shakers, knives, forks, and spoons. Using the right software, one system (the mind) can be mapped onto the other (the computer). ”
–George Johnson

2. HW7/Proj2 Questions/Concerns?

3. A Homework 5 Comment

4. Horn Clauses
*(From the class notes. Shapiro, 2010.)

5. Prolog Control+D to exit consult(user). Horn clause resolution.
From the notes:
| ?- consult(user).
% consulting user...
| driver(X) :- drives(X,_).
| passenger(Y) :- drives(_,Y).
| drives(betty,tom). |
% consulted user in module user, 0 msec 1200 bytes
yes
| ?- driver(X), passenger(Y).
X = betty,
Y = tom ? y

6. Prolog Closed World Assumption
Nothing exists outside of the KB defined in your prolog program.
| ?- consult(user).
% consulting user...
| hero(superman).
| hero(theflash).
| hero(greenlantern). |
% consulted user in module user, 0 msec 784 bytes
yes
| ?- hero(superman).
| ?- hero(batman). no

7. Prolog Example