anchor.diff:  chk_msgs(Msgs) when is_integer(Msgs) -> Msgs;
   chk_msgs(X) -> exit({bad_msgs,X}).
   
  -chk_trc('send',{Flags,RTPs}) -> {['send'|Flags],RTPs};
  -chk_trc('receive',{Flags,RTPs}) -> {['receive'|Flags],RTPs};
  +chk_trc('send',{Flags,RTPs})                 -> {['send'|Flags],RTPs};
  +chk_trc('receive',{Flags,RTPs})              -> {['receive'|Flags],RTPs};
  +chk_trc('arity',{Flags,RTPs})                -> {['arity'|Flags],RTPs};
   chk_trc(RTP,{Flags,RTPs}) when is_tuple(RTP) -> {Flags,[chk_rtp(RTP)|RTPs]};
  -chk_trc(X,_) -> exit({bad_trc,X}).
  +chk_trc(X,_)                                 -> exit({bad_trc,X}).
   
   chk_rtp({M})                             -> chk_rtp({M,'_',[]});
   chk_rtp({M,F}) when is_atom(F)           -> chk_rtp({M,F,[]});
  
positive.code:              , proc         = all          % list of procs (or 'all')
  	     , targ         = node()       % target node
  	     , buffered     = no           % output buffering
               , print_form   = "~s~n"       % format for printing
  	     , print_file   = ""           % file to print to (standard_io)
               , print_re     = ""           % regexp that must match to print
  
negative.code:            , "Proc: 'all'|pid()|atom(Regname)|{'pid',I2,I3}"
             , "Targ: node()"
             , "RMSs: (restricted match specs): list(RMS)"
             , "RMS: 'stack'|'return'|integer(Arity)|tuple(ArgDescriptor)"
             , "ArgDescriptor: '_'|literal()"
             , ""
             , "Opts: list({Opt,Val})"
  