(CommandList
  children: [
    (C {(echo)} {(SQ <'--- tai64n has the right format'>)})
    (Pipeline
      children: [
        (Subshell
          child: 
            (CommandList
              children: [
                (Sentence child:(C {(echo)} {(ONE)}) terminator:<Op_Semi ';'>)
                (C {(echo)} {(TWO)})
              ]
            )
          spids: [17 28]
        )
        (C {(tai64n)})
        (C {(sed)} {(SQ <'s/[0-9a-f]/x/g'>)})
      ]
      negated: F
    )
    (C {(echo)} {(SQ <'--- tai64nlocal handles non-@ lines correctly'>)})
    (CommandList
      children: [
        (Sentence
          child: 
            (Pipeline
              children: [
                (Subshell
                  child: 
                    (CommandList
                      children: [
                        (Sentence
                          child: (C {(echo)} {(one)})
                          terminator: <Op_Semi ';'>
                        )
                        (C {(echo)} {(two)})
                      ]
                    )
                  spids: [49 60]
                )
                (C {(tai64nlocal)})
              ]
              negated: F
            )
          terminator: <Op_Semi ';'>
        )
        (C {(echo)} {($ VSub_QMark '$?')})
      ]
    )
  ]
)