final_2009 - Name email 6.034 Final Examination Circle your...

Name
email
6.034 Final Examination
December 16, 2009
Circle your TA and principle recitation instructor so that we can more easily identify
with whom you have studied:
Erica Cooper Matthew Peairs Mark Seifter
Yuan Shen Jeremy Smith Olga Wichrowska
Robert Berwick Randall Davis Gregory Martin
Indicate the approximate percent of the lectures, mega recitations, recitations, and tutorials you have
attended so that we can better gauge their correlation with quiz and final performance. Your answers
have no effect on your grade.
Lectures Recitations Megas Tutorials
Percent attended
Quiz Score Grader
Q1
Q2
Q3
Q4
Q5
There are 38 pages in this final examination, including this one. In addition, tear-
off sheets are provided at the end with duplicate drawings and data. As always,
open book, open notes, open just about everything.
1

Quiz 1, Problem 1, Rules (50 points)
The administration, worried about the social habits of its students, agrees to finance cross-school-
mixers. The 034 TA's decide to fly to England and mix with the students at Hogwarts School of
Witchcraft and Wizardry. A merry old time ensues, but the morning after, due to an accidental
confundo charm (and perhaps also a large consumption of butterbeer), no one can remember the events
that transpired. The 034 staff, in an attempt to show off the power of Muggle logic, promise they can
piece together the important events with a rule based system.
Using their keen sense of logic, Matt, Erica, and Mark are able to piece together the following rules:
RULES:
R0 : IF (?X) goes to MIT,
THEN (?X) is a muggle,
(?X) consumed butterbeer
R1: IF (?X) made math jokes AND
(?X) consumed butterbeer
THEN (?X) was transfigured into a porcupine
R2: IF (?Y) fancies (?X) AND
(?X) fancies (?Y) AND
(?Y) is a muggle
THEN (?X) snogged (?Y)
R3: IF (?X) fancies (?Y) AND
(?X) made math jokes,
THEN (?Y) fancies (?X)
R4: IF (?X) made math jokes
THEN (?X) goes to MIT
You start with the following list of assertions which is all you have to go on.
ASSERTIONS:
A0: Olga made math jokes
A1: Yuan goes to MIT
A2: Jeremy made math jokes
A3: Hermione consumed butterbeer
A4: Jeremy fancies Hermione
2

Part A: Forward Chaining (24 points)
Run forward chaining on the rules and assertions provided for the first 5 iterations. For the first
two iterations, fill out the first two rows in the table below, noting the rules whose antecedents match
the data, the rule that fires, and the new assertions that are added by the rule. For the remainder, supply
only the fired rules and new assertions. As usual, break ties using the earliest rule on the list that
matches. If the earliest rule matches more than once, break ties by assertion order.
Matched Fired New assertions added to database
1
2
3
4
5
3

Part B: Backward Chaining (26 points)
Ron Weasley claims that Hermione snogged Jeremy. Use backward chaining to determine if this event
occurred. Draw the goal tree for this statement . Partial credit will be given for partial completion of
the goal tree.