(CommandList
  children: [
    (Sentence
      child: 
        (Assignment
          keyword: Assign_None
          pairs: [
            (assign_pair
              lhs: (LhsName name:SRCDIR)
              op: Equal
              rhs: 
                {
                  (DQ 
                    (CommandSubPart
                      command_list: 
                        (CommandList
                          children: [(C {(dirname)} {(DQ (${ VSub_Number 0))})]
                        )
                      left_token: <Left_CommandSub '$('>
                      spids: [9 17]
                    )
                  )
                }
              spids: [7]
            )
          ]
          spids: [7]
        )
      terminator: <Op_Semi ';'>
    )
    (C {(export)} {(SRCDIR)})
    (Pipeline
      children: [
        (C {(m4)} {(DQ (${ VSub_Name SRCDIR) (/../regress.m4))} 
          {(DQ (${ VSub_Name SRCDIR) (/regress.sh))}
        )
        (C {(sh)})
      ]
      negated: False
    )
  ]
)