untypeStmt' (Loop from inv untl body var) =
  Loop (untypeStmt from)
       (map untypeClause inv)
       (untypeExpr untl)
       (untypeStmt body)
       (untypeExpr <$> var)
untypeStmt' (Loop from inv untl body var) =
  Loop (untypeStmt from)
       (map untypeClause inv)
       (untypeExpr untl)
       (untypeStmt body)
       (untypeExpr <$> var)
untypeStmt' (Loop from inv untl body var) =
  Loop (untypeStmt from)
       (map untypeClause inv)
       (untypeExpr untl)
       (untypeStmt body)
       (untypeExpr <$> var)