anchor.diff:             , ""
              , "Trc: list('send'|'receive'|{M}|{M,F}|{M,RMSs}|{M,F,RMSs})"
              , "Proc: 'all'|pid()|atom(Regname)|{'pid',I2,I3}"
  -           , "Targ: node()"
  +           , "Target: node()"
              , "RMSs: (restricted match specs): list(RMS)"
              , "RMS: 'stack'|'return'|integer(Arity)|tuple(ArgDescriptor)"
              , "ArgDescriptor: '_'|literal()"
  
positive.code:   case whereis(redbug) of
      undefined -> 
        Cnf = make_cnf(Trc,Props),
        try 
          register(redbug, spawn(fun init/0)),
          redbug ! {start,Cnf},
  
negative.code:            , "time         (15000)       stop trace after this many ms"
             , "msgs         (10)          stop trace after this many msgs"
             , "proc         (all)         (list of) Erlang process(es)"
             , "target       (node())      node to trace on"
             , "arity        (false)       print arity instead of arg list"
             , "  print-related opts"
             , "max_queue    (5000)        fail if internal queue gets this long"
  