extractTUnquotes n (TSeq tac1 tac2)
  = do (tac1', ex1) <- extractTUnquotes n tac1
       (tac2', ex2) <- extractTUnquotes n tac2
       return (TSeq tac1' tac2', ex1 ++ ex2)
extractTUnquotes n (TSeq tac1 tac2)
  = do (tac1', ex1) <- extractTUnquotes n tac1
       (tac2', ex2) <- extractTUnquotes n tac2
       return (TSeq tac1' tac2', ex1 ++ ex2)
extractTUnquotes n (TSeq tac1 tac2)
  = do (tac1', ex1) <- extractTUnquotes n tac1
       (tac2', ex2) <- extractTUnquotes n tac2
       return (TSeq tac1' tac2', ex1 ++ ex2)