(command.CommandList children: [ (command.If arms: [ (if_arm cond: (condition.Shell commands: [ (command.Sentence child: (C {<Id.Lit_LBracket '['>} {($ Id.VSub_Pound '$#')} {<-ne>} {<2>} {<Id.Lit_RBracket ']'>} ) terminator: <Id.Op_Semi _> ) ] ) action: [ (command.Simple words: [{<echo>} {(DQ <'Usage '> ($ Id.VSub_Number '$0') <' from to'>)}] redirects: [(redir op:<Id.Redir_GreatAnd '>&'> loc:(redir_loc.Fd fd:1) arg:{<2>})] do_fork: T ) (command.Simple words: [{<echo>} {(DQ <'for e.g. '> ($ Id.VSub_Number '$0') <' \'2 grams\' drams'>)}] redirects: [(redir op:<Id.Redir_GreatAnd '>&'> loc:(redir_loc.Fd fd:1) arg:{<2>})] do_fork: T ) (command.ControlFlow token:<Id.ControlFlow_Exit exit>) ] spids: [15 28] ) ] ) (C {<units>} {<-t>} {(DQ ($ Id.VSub_Number '$1'))} {(DQ ($ Id.VSub_Number '$2'))}) ] )