yy_reduce_print (YYSTYPE *yyvsp, int yyrule)
#else
static void
yy_reduce_print (yyvsp, yyrule)
    YYSTYPE *yyvsp;
    int yyrule;
#endif
{
  int yynrhs = yyr2[yyrule];
  int yyi;
  unsigned long int yylno = yyrline[yyrule];
  YYFPRINTF (stderr, "Reducing stack by rule %d (line %lu):\n",
	     yyrule - 1, yylno);
  /* The symbols being reduced.  */
  for (yyi = 0; yyi < yynrhs; yyi++)
    {
      YYFPRINTF (stderr, "   $%d = ", yyi + 1);
      yy_symbol_print (stderr, yyrhs[yyprhs[yyrule] + yyi],
		       &(yyvsp[(yyi + 1) - (yynrhs)])
		       		       );
      YYFPRINTF (stderr, "\n");
    }
}

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.