22 lines
440 B
Prolog
22 lines
440 B
Prolog
grade(alice, a).
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grade(bob, b).
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grade(carol, a).
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grade(dave, c).
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got_an_a(Student) :-
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grade(Student, Grade),
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Grade = a.
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did_not_get_an_a(Student) :-
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grade(Student, Grade),
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Grade \= a.
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:- initialization(main).
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main :-
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write("While "),
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got_an_a(X),
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write(X), write(" got an A, "), fail;
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write("but "),
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did_not_get_an_a(Y),
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write(Y), write(" did not get an A, "), fail; write("unfortunately."), nl.
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