42 lines
602 B
Plaintext
42 lines
602 B
Plaintext
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:- object(log(_),
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implements(symdiffp)).
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:- info([
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authors is 'Paulo Moura',
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version is 1.0,
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date is 1999/12/29,
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parnames is ['Expression'],
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comment is 'Symbolic differentiation and simplification of log/1 expressions.',
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source is 'Example based on the Clocksin and Mellish Prolog book.']).
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diff(Diff) :-
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this(log(X)),
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once(diff(X, Diff)).
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diff(I, 0) :-
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integer(I).
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diff(X, DX * X ** -1) :-
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X::diff(DX).
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simplify(S) :-
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this(log(X)),
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once(simplify(X, S)).
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simplify(1, 0).
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simplify(I, Log) :-
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integer(I),
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Log is log(I).
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simplify(X, X).
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:- end_object.
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