getVarsTerm (Mixfix_braced ts _) =
    foldr (Map.unionWith Set.union . getVarsTerm) Map.empty ts
getVarsTerm (Mixfix_braced ts _) =
    foldr (Map.unionWith Set.union . getVarsTerm) Map.empty ts
getVarsTerm (Mixfix_braced ts _) =
    foldr (Map.unionWith Set.union . getVarsTerm) Map.empty ts