code: def rule_function_not_found(self, fun=None):
          
          sfun = str(fun)
          self.cry('rule_function_not_found:' + sfun)
  
          def not_found(*a, **k):
              return(sfun + ':rule_function_not_found', k.keys())
          return not_found
docs: any function that does not exist will be added as a
          dummy function that will gather inputs for easing into
          the possible future implementation