(command.CommandList
  children: [
    (command.ShAssignment
      pairs: [
        (assign_pair
          lhs: (sh_lhs_expr.Name name:hgDir)
          op: assign_op.Equal
          rhs: 
            {
              (command_sub
                left_token: <Id.Left_Backtick '`'>
                child: (C {<dirname>} {($ Id.VSub_Number '$0')})
              ) <'/..'>
            }
          spids: [50]
        )
      ]
    )
    (command.Sentence
      child: 
        (command.If
          arms: [
            (if_arm
              cond: 
                (condition.Shell
                  commands: [
                    (command.Sentence
                      child: 
                        (command.DBracket
                          expr: 
                            (bool_expr.LogicalAnd
                              left: (bool_expr.Unary op_id:Id.BoolUnary_x child:{<'/usr/bin/hg'>})
                              right: 
                                (bool_expr.Unary
                                  op_id: Id.BoolUnary_d
                                  child: {($ Id.VSub_DollarName '$hgDir') <'/.hg'>}
                                )
                            )
                        )
                      terminator: <Id.Op_Semi _>
                    )
                  ]
                )
              action: [
                (command.ShAssignment
                  pairs: [
                    (assign_pair
                      lhs: (sh_lhs_expr.Name name:rev)
                      op: assign_op.Equal
                      rhs: 
                        {(command_sub left_token:<Id.Left_Backtick '`'> child:(C {<hg>} {<id>} {<-i>}))}
                      spids: [82]
                    )
                  ]
                )
              ]
              spids: [60 79]
            )
            (if_arm
              cond: 
                (condition.Shell
                  commands: [
                    (command.Sentence
                      child: 
                        (C {<Id.Lit_LBracket '['>} {<-f>} 
                          {($ Id.VSub_DollarName '$hgDir') <'/.hg_archival.txt'>} {<Id.Lit_RBracket ']'>}
                        )
                      terminator: <Id.Op_Semi _>
                    )
                  ]
                )
              action: [
                (command.Sentence
                  child: 
                    (command.ShAssignment
                      pairs: [
                        (assign_pair
                          lhs: (sh_lhs_expr.Name name:rev)
                          op: assign_op.Equal
                          rhs: 
                            {
                              (command_sub
                                left_token: <Id.Left_Backtick '`'>
                                child: 
                                  (command.Pipeline
                                    children: [
                                      (C {<grep>} {<node>} 
                                        {($ Id.VSub_DollarName '$hgDir') <'/.hg_archival.txt'>}
                                      )
                                      (C {<cut>} {<-d> (SQ <' '>)} {<-f>} {<2>})
                                      (C {<head>} {<-c>} {<12>})
                                    ]
                                    negated: F
                                  )
                              )
                            }
                          spids: [108]
                        )
                      ]
                    )
                  terminator: <Id.Op_Semi _>
                )
              ]
              spids: [93 105]
            )
          ]
          else_action: [
            (command.Sentence
              child: 
                (command.ShAssignment
                  pairs: [
                    (assign_pair
                      lhs: (sh_lhs_expr.Name name:rev)
                      op: assign_op.Equal
                      rhs: (word.Empty)
                      spids: [143]
                    )
                  ]
                )
              terminator: <Id.Op_Semi _>
            )
          ]
        )
      terminator: <Id.Op_Semi _>
    )
    (C {<echo>} {(DQ ($ Id.VSub_DollarName '$rev'))})
  ]
)