(command.CommandList
  children: [
    (C {<Id.Lit_Colon ':'>} {(SQ <'This file is in the public domain, so clarified as of'>)})
    (C {<Id.Lit_Colon ':'>} {(SQ <'2006-07-17 by Arthur David Olson.'>)})
    (C {<Id.Lit_Colon ':'>} {(SQ <'@(#)yearistype.sh\t8.2'>)})
    (command.Case
      to_match: {($ Id.VSub_Pound '$#') <-> ($ Id.VSub_Number '$1')}
      arms: [
        (case_arm
          pat_list: [
            {<2->}
            {<2-0> <Id.Lit_Star '*'>}
            {<2-> <Id.Lit_Star '*'> <Id.Lit_LBracket '['> <Id.KW_Bang '!'> <0-9> <Id.Lit_RBracket ']'> 
              <Id.Lit_Star '*'>
            }
          ]
          action: [
            (command.Simple
              words: [{<echo>} {(DQ ($ Id.VSub_Number '$0') <': wild year - '> ($ Id.VSub_Number '$1'))}]
              redirects: [(redir op:<Id.Redir_GreatAnd '>&'> loc:(redir_loc.Fd fd:1) arg:{<2>})]
              do_fork: T
            )
            (command.ControlFlow token:<Id.ControlFlow_Exit exit> arg_word:{<1>})
          ]
          spids: [33 45 64 -1]
        )
      ]
    )
    (command.Case
      to_match: {($ Id.VSub_Pound '$#') <-> ($ Id.VSub_Number '$2')}
      arms: [
        (case_arm
          pat_list: [{<2-even>}]
          action: [
            (command.Case
              to_match: {($ Id.VSub_Number '$1')}
              arms: [
                (case_arm
                  pat_list: [{<Id.Lit_Star '*'> <Id.Lit_LBracket '['> <24680> <Id.Lit_RBracket ']'>}]
                  action: [(command.ControlFlow token:<Id.ControlFlow_Exit exit> arg_word:{<0>})]
                  spids: [89 93 99 -1]
                )
                (case_arm
                  pat_list: [{<Id.Lit_Star '*'>}]
                  action: [(command.ControlFlow token:<Id.ControlFlow_Exit exit> arg_word:{<1>})]
                  spids: [102 103 109 -1]
                )
              ]
            )
          ]
          spids: [78 79 114 -1]
        )
        (case_arm
          pat_list: [{<2-nonpres>} {<2-nonuspres>}]
          action: [
            (command.Case
              to_match: {($ Id.VSub_Number '$1')}
              arms: [
                (case_arm
                  pat_list: [
                    {<Id.Lit_Star '*'> <Id.Lit_LBracket '['> <02468> <Id.Lit_RBracket ']'> 
                      <Id.Lit_LBracket '['> <048> <Id.Lit_RBracket ']'>
                    }
                    {<Id.Lit_Star '*'> <Id.Lit_LBracket '['> <13579> <Id.Lit_RBracket ']'> 
                      <Id.Lit_LBracket '['> <26> <Id.Lit_RBracket ']'>
                    }
                  ]
                  action: [(command.ControlFlow token:<Id.ControlFlow_Exit exit> arg_word:{<1>})]
                  spids: [130 145 151 -1]
                )
                (case_arm
                  pat_list: [{<Id.Lit_Star '*'>}]
                  action: [(command.ControlFlow token:<Id.ControlFlow_Exit exit> arg_word:{<0>})]
                  spids: [154 155 161 -1]
                )
              ]
            )
          ]
          spids: [117 120 166 -1]
        )
        (case_arm
          pat_list: [{<2-odd>}]
          action: [
            (command.Case
              to_match: {($ Id.VSub_Number '$1')}
              arms: [
                (case_arm
                  pat_list: [{<Id.Lit_Star '*'> <Id.Lit_LBracket '['> <13579> <Id.Lit_RBracket ']'>}]
                  action: [(command.ControlFlow token:<Id.ControlFlow_Exit exit> arg_word:{<0>})]
                  spids: [180 184 190 -1]
                )
                (case_arm
                  pat_list: [{<Id.Lit_Star '*'>}]
                  action: [(command.ControlFlow token:<Id.ControlFlow_Exit exit> arg_word:{<1>})]
                  spids: [193 194 200 -1]
                )
              ]
            )
          ]
          spids: [169 170 205 -1]
        )
        (case_arm
          pat_list: [{<2-uspres>}]
          action: [
            (command.Case
              to_match: {($ Id.VSub_Number '$1')}
              arms: [
                (case_arm
                  pat_list: [
                    {<Id.Lit_Star '*'> <Id.Lit_LBracket '['> <02468> <Id.Lit_RBracket ']'> 
                      <Id.Lit_LBracket '['> <048> <Id.Lit_RBracket ']'>
                    }
                    {<Id.Lit_Star '*'> <Id.Lit_LBracket '['> <13579> <Id.Lit_RBracket ']'> 
                      <Id.Lit_LBracket '['> <26> <Id.Lit_RBracket ']'>
                    }
                  ]
                  action: [(command.ControlFlow token:<Id.ControlFlow_Exit exit> arg_word:{<0>})]
                  spids: [219 234 240 -1]
                )
                (case_arm
                  pat_list: [{<Id.Lit_Star '*'>}]
                  action: [(command.ControlFlow token:<Id.ControlFlow_Exit exit> arg_word:{<1>})]
                  spids: [243 244 250 -1]
                )
              ]
            )
          ]
          spids: [208 209 255 -1]
        )
        (case_arm
          pat_list: [{<2-> <Id.Lit_Star '*'>}]
          action: [
            (command.Simple
              words: [{<echo>} {(DQ ($ Id.VSub_Number '$0') <': wild type - '> ($ Id.VSub_Number '$2'))}]
              redirects: [(redir op:<Id.Redir_GreatAnd '>&'> loc:(redir_loc.Fd fd:1) arg:{<2>})]
              do_fork: T
            )
          ]
          spids: [258 260 274 -1]
        )
      ]
    )
    (command.Simple
      words: [
        {<echo>}
        {
          (DQ ($ Id.VSub_Number '$0') <': usage is '> ($ Id.VSub_Number '$0') 
            <' year even|odd|uspres|nonpres|nonuspres'>
          )
        }
      ]
      redirects: [(redir op:<Id.Redir_GreatAnd '>&'> loc:(redir_loc.Fd fd:1) arg:{<2>})]
      do_fork: T
    )
    (command.ControlFlow token:<Id.ControlFlow_Exit exit> arg_word:{<1>})
  ]
)