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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def to_funset(self):
 """ Converts the experimental setup to a set of `gringo.Fun`_ object instances Returns ------- set The set of `gringo.Fun`_ object instances .. _gringo.Fun: http://potassco.sourceforge.net/gringo.html#Fun """

        fs = set((gringo.Fun('stimulus', [str(var)]) for var in self.stimuli))
        fs = fs.union((gringo.Fun('inhibitor', [str(var)]) for var in self.inhibitors))
        fs = fs.union((gringo.Fun('readout', [str(var)]) for var in self.readouts))

        return fs