@property
def prolog_variables(self):
    'Return filtered prolog variables'
    if (not self._prolog_visitor):
        self.dependency_filter.run()
        self._prolog_visitor = PrologVisitor(self.dependency_filter)
        self._prolog_visitor.visit(self.dependency_filter.main_cluster)
    return self._prolog_visitor
Return filtered prolog variables
@property
def prolog_variables(self):
    
    if (not self._prolog_visitor):
        self.dependency_filter.run()
        self._prolog_visitor = PrologVisitor(self.dependency_filter)
        self._prolog_visitor.visit(self.dependency_filter.main_cluster)
    return self._prolog_visitor