def undefine(self):
if lib.EnvUndefrule(self._env, self._rule) != <NUM_LIT:1>:<EOL><INDENT>raise CLIPSError(self._env)<EOL><DEDENT>self._env = None<EOL>
Undefine the Rule.

        Python equivalent of the CLIPS undefrule command.

        The object becomes unusable after this method has been called.