The Scene You are just starting a quiet evening at home when an old friend calls

Question

The Scene
You are just starting a quiet evening at home when an old friend calls to announce he is coming over for dinner at your place. This being a big surprise, you immediately undertake emergency dinner preparations.

Within a few minutes, you have managed to load up the BARTENDER expert system on your personal computer so that you can select a beverage. BARTENDER is a backward-chaining production system with rules given below. For example, rule B1 would read as "if expensive wine is indicated and it is New Year's Eve, then drink Bond's Champagne." Note that when more than one rule has a consequent matching the current problem, those rules are tried in the order given in the list. Furthermore, within a rule the antecedents are to be tested in the order provided. That is, to check rule B1 one must check whether expensive wine is indicated before checking if it is New Year's Eve.

Rule Antecedents Conclusion
B1 expensive wine is indicated and
it is New Year's Eve drink Bond's Champagne
B2 expensive wine is indicated and
entree is based on steak drink Chateau Earl of Bartonville Red
B3 cheap wine is indicated and
entree is based on chicken and
guest is not well liked drink Honest Henry's Apple Wine
B4 cheap wine is indicated and
entree is unknown drink Toe Lakes Rose
B5 beer is indicated and
entree style is Mexican drink Dos Equis
B6 beer is indicated drink Coors
B7 guest is a health nut drink Glop
B8 guest is a health nut and
carrots are not to be served drink carrot juice
B9 wine is indicated and
guest should be impressed expensive wine is indicated
B10 wine is indicated cheap wine is indicated
B11 guest is sophisticated wine is indicated
B12 entree style is Mexican beer is indicated
B13 guest is not well liked and
entree is catered by Death-wish Caterers beer is indicated
B14 true drink water


Exercises
1. Simulate BARTENDER's behavior on the following facts:

o Assume each of the following facts is true if inquired:
? T1: Entree is catered by Death-Wish Caterers
? T2: Carrots are to be served.
? T3: Guest is well liked
? T4: Guest is sophisticated.
? T5: It is New Year's Eve.
? T6: Entree is unknown.

o Assume each of the following facts is false if inquired:
? F1: Guest is a health nut.
? F2: Guest should be impressed
? F3: The entree is based on steak.
? F4: The entree is based on chicken.
? F5: Entree style is Mexican

A. In simulating the expert system, attempt to prove the drink predicates in the order listed. That is, you should attempt to prove the desired drink is Bond's Champagne (rule B1) before attempting to prove its Chateau Earl of Bartonville Red (rule B2), and so on. Show all attempts; that is, show each rule being tested including both failures and successes. Stop when you reach the first conclusion! Don't forget that an Expert System will never re-compute the same conclusion; once something has been shown to be true or false, that information is stored for future use.


B. List the identifiers of the facts (things which were true and which were used) in the order that they first occurred while doing problem 1. For example, if you used "the entree is not based on chicken", "guest is a health nut", "the entree is not based on chicken" (which was already asked earlier), and "carrots are to be served" (in that order), you'd list F4, F1, T2.

C. With a different set of facts, could BARTENDER ever recommend Glop with steak? Why or why not?


D. Why shouldn't rule B6 be listed before rule B5?

Explanation / Answer

Hi i have solved this question in my notebook, but i can't type it and post it here because time has expired please rate me lifesaver and i'll make sure the answer is in your inbox! or my effort and time would go all in vain i don't do this generally but i am doing because of the circumstances

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