-- Provides default implementations that do nothing.
trivialBuiltInFamily :: BuiltInSynFamily
trivialBuiltInFamily = BuiltInSynFamily
  { sfMatchFam      = \_ -> Nothing
  , sfInteractTop   = \_ _ -> []
  , sfInteractInert = \_ _ _ _ -> []
  }
trivialBuiltInFamily :: BuiltInSynFamily
trivialBuiltInFamily = BuiltInSynFamily
  { sfMatchFam      = \_ -> Nothing
  , sfInteractTop   = \_ _ -> []
  , sfInteractInert = \_ _ _ _ -> []
  }
trivialBuiltInFamily = BuiltInSynFamily
  { sfMatchFam      = \_ -> Nothing
  , sfInteractTop   = \_ _ -> []
  , sfInteractInert = \_ _ _ _ -> []
  }