anchor.diff:               , location(State1)
                ),
   
  -  OldSupressRead = case erlang:get(supress_read) of
  +  OldSupressRead = case erlang:get(?SUPPRESS_READ) of
                        undefined -> false;
                        SR -> SR
                      end,
     SupressRead    = OldSupressRead orelse ReadCondOpt == preserve,
  -  erlang:put(supress_read, SupressRead),
  +  erlang:put(?SUPPRESS_READ, SupressRead),
   
     try
       case SupressRead of
  
positive.code:   catch ?WITH_STACKTRACE(error, Reason, Stack)
        ?ERROR(Reason, location(NewState), Stack)
    after
      erlang:erase(gensym_env)
    end.
  
  -spec syntax_quote(any()) -> any().
  
negative.code:     ?NIL ->
        ArgSymbol = gen_arg_sym(N),
        NewArgEnv = maps:put(N, ArgSymbol, ArgEnv),
        erlang:put(?ARG_ENV, NewArgEnv),
        ArgSymbol;
      ArgSymbol -> ArgSymbol
    end.
  