University of Toronto - Fall
2006
Department of Computer Science
CSC 486/2502: Knowledge Representation and Reasoning
Assignment 1 Clarification Page
Question 1
Oct 2: I believe these points are clear from the problem statement, but since
the question was asked in class.
- The question says "Show that no barber can fulfill these requirements."
In your FOL representation, do not create a constant symbol representing
"the town barber".
- Regarding the proof, we are expecting a semantic proof along the lines
of the ones we've been doing in class.
Question 3
Oct 2: We'll discuss the tableau algorithm again briefly in
tutorial on Tuesday October 3.
Question 4
Oct 10: Update on Experiments.
- As we foresaw, experimenting with 50-variable formulae has been
taking up too much compute time for those running their experiments on CSLab or
CDF. As discussed on Friday, if you are experiencing this problem,
please make a reasonable
choice and note your decision in your write-up.
Experiments in the 12-16 variable range have been working and
are a reasonable compromise. You will probably not obtain a curve such
as the one in Mitchell et al.'s paper.
You should observe though, that as the number of
clauses increases, the proportion of unsatisfiable KBs increases.
Please try to explain the
shape of your curve in your write-up, particularly if it differs from
the Mitchell et al. graph.
Oct 10: Clarification on late policy.
If you want to hand in the written part of your assignment late, please
email Sheila to let her know and she'll make special arrangements with
you. 1 day late: due Sat Oct 14, 4pm; 2 days late: due Sun Oct 15, 4pm,
3 days late: due Mon Oct 16, 4pm. Remember you have 3 grace days.
Alternatively, the late penalty is 20% per day.
Oct 10: Your random clause generator should not generate clauses
that mention a propositional letter twice.
E.g., the following clauses should not
be generated by your program: (1 3 1), (5 8 -5).
Back to the main page