@type t() ::
  {:response, a :: String.t(), b :: String.t()}
  | {:precedence, a :: String.t(), b :: String.t()}
  | {:non_coexistence, a :: String.t(), b :: String.t()}
  | {:chain_response, a :: String.t(), b :: String.t()}
  | {:exactly_once, a :: String.t()}
  | {:absence, a :: String.t()}
  | {:and, [t()]}
  | {:or, [t()]}