:- object(x,
	implements(symdiffp)).


	:- info([
		author is 'Paulo Moura',
		version is 1.0,
		date is 1999/12/29,
		comment is 'Symbolic differentiation and simplification of a variable.',
		source is 'Example based on the Clocksin and Mellish Prolog book.']).


	diff(1).


	simplify(x).


:- end_object.