rem: value = ! one_argument (argv[pos+1]);
add: { advance (false); value = ! one_argument (); }
context: two_arguments (void){  int value;  if (STREQ (argv[pos], "!"))    value = ! one_argument (argv[pos+1]);  else if (argv[pos][0] == '-'	   && argv[pos][1] != '\0'	   && argv[pos][2] == '\0')    {      if (unop (argv[pos][1]))	value = unary_operator ();      else	test_syntax_error (_("%s: unary operator expected\n"), argv[pos]);    }  else    beyond ();  return (value);}