Information Technology Reference
In-Depth Information
1. The occupant of the red house is English.
2. The Spaniard owns a dog.
3. The coffee drinker lives in a green house.
4. The Ukrainian drinks tea.
5. The ivory house is to the left of the green one.
6. The snail owner smokes Winstons.
7. The person in the yellow house smokes Kools.
8. The occupant in the middle house drinks milk.
9. The Norwegian lives in the leftmost house.
10. The Chesterfield smoker lives next to the fox owner.
11. The Kool smoker lives next to the horse owner.
12. The orange juice drinker smokes Lucky Strikes.
13. The Parliament smoker is Japanese.
14. The Norwegian lives next to a blue house.
Who owns the zebra?
Observe that most of these clues will end up being statements of equality among the
variables:
4.
The Ukrainian drinks tea.
Ukrainian = TeaDrinker
6.
The snail owner smokes Winstons.
SnailOwner = WinstonSmoker
The question is what to do about the constraints involving
position
:
5.
The ivory house is to the left of the green one.
(Note that
left
here means directly to the left.) This fact needs to relate to other
positional constraints like the following:
8.
The occupant in the middle house drinks milk.
9.
The Norwegian lives in the leftmost house.
10.
The Chesterfield smoker lives next to the fox owner.
First determine what
domain
to use for the variables. As long as the appropriate equal-
ity and inequality constraints are enforced, the values can be taken from any set. The
