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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 execute(self, logical_form: str):
 """Executes a logical form, using whatever predicates you have defined."""

        if not hasattr(self, '_functions'):
            raise RuntimeError("You must call super().__init__() in your Language constructor")
        logical_form = logical_form.replace(",", " ")
        expression = util.lisp_to_nested_expression(logical_form)
        return self._execute_expression(expression)