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## Exercises

1. What knowledge representation schemes met so far are most suited to the forms of reasoning discussed in the lectures?
1. Discuss how they might deal with Incompleteness, inconsistency, change and and non-monotonic default reasoning.
2. What knowledge forms are totally inadequate for uncertain reasoning?
2. Rewrite the President Nixon example using abnormal predicates.
3. Use circumscription to resolve the President Nixon example.
4. Consider the problem of deciding which clothes to wear using knowledge such as:

• Wear casual clothes unless they are not clean or important meeting occurs today.
• Wear a Sweater if it is cold.
• The winter is usually cold.
• Wear shorts if it's warm.
• The summer is usually warm.

1. Construct a JTMS network to represent these facts.
2. Try to solve the problem In winter do I wear shorts?
3. Answer the question What shall I wear today (You may assume that the system knows the time of year).
5. Construct as JTMS and ATMS to represent the following

1. If you have spots and a temperature you have measles.
2. If you have a runny nose then unless it is hay fever season you have a cold.
6. Show how a JTMS could be used to facilitate constraint satisfaction problems and in particular cryptarithmetic puzzles.
7. Show how an ATMS could be used to facilitate constraint satisfaction problems and in particular cryptarithmetic puzzles.
8. Design a depth first based algorithm to search or label a JTMS.
9. Design a breadth first based algorithm to search or label an ATMS.
10. Use an ATMS to solve the following car diagnostic problem.

You may assume the following:

• If the battery is OK and the headlight bulbs are OK then the headlights will work.
• If the battery is OK and the starter is OK then the engine will start.

Find explanations as to why:

• The engine won't start but the headlights work.
• the headlights won't work but the car starts.

Next: Uncertain Reasoning: Statistical Methods Up: Reasoning with Uncertainty: Non-Monotonic Previous: Further Reading

dave@cs.cf.ac.uk