title: Fatal Error with Smarty - Unknown tag 'math'
body: <p>I am using PHP 8 and Smarty 4.0.0 version.
  I have used math equation in my .tpl file.</p>
  <pre><code>
  {assign var=total value=0}
  {section name=i start=0 loop=$serial_list|@count}
  {math assign=&quot;total&quot; equation=&quot;a&quot; a=$serial_list|@count}
  &lt;tr class=&quot;&quot; &gt;
  &lt;td  width=&quot;5%&quot; align='center' valign='middle'&gt;&lt;strong&gt;{$smarty.section.i.index+1}&lt;/strong&gt; &lt;/td&gt;
  &lt;td width=&quot;6%&quot;&gt;{$serial_list[i].serial_no}&lt;/td&gt;
  &lt;td width=&quot;5%&quot;&gt;{$serial_list[i].prod_ord_no}&lt;/td&gt;
  &lt;td width=&quot;5%&quot;&gt;{$serial_list[i].mat_code}&lt;/td&gt;
  &lt;td width=&quot;5%&quot;&gt;{$serial_list[i].batch_no}&lt;/td&gt;
  &lt;td width=&quot;4%&quot;&gt;{$serial_list[i].gp_batch_no}&lt;/td&gt; 
  &lt;td width=&quot;8%&quot;&gt;{$serial_list[i].mat_size}&lt;/td&gt;
  &lt;td width=&quot;9%&quot;&gt;&amp;nbsp;{$serial_list[i].mat_desc}&lt;/td&gt;
  &lt;td width=&quot;5%&quot;&gt;&amp;nbsp;{$serial_list[i].insp_lot_no}&lt;/td&gt; 
  &lt;td width=&quot;5%&quot;&gt;&amp;nbsp;{$serial_list[i].mfg_date}&lt;/td&gt;
  &lt;td width=&quot;5%&quot;&gt;&amp;nbsp;{$serial_list[i].exp_date}&lt;/td&gt; 
  
  &lt;/tr&gt;
  {/section}
  
  
  </code></pre>
  <p>But smarty errors:</p>
  <pre>
  >Fatal error: Uncaught --> Smarty Compiler: Syntax error in template >"file:C:\xampp8\htdocs\test\smarty\templates\reports\get_gp_data_from_sap.tpl" on line 110 "{math >equation="x + y" x='5' y='5'}" unknown tag 'math' C:\xampp8\htdocs\test\smarty\libs\sysplugins\smarty_internal_templatecompilerbase.php on line 110
  
  </pre>
  <p>How can I solve this?</p>