1. Go to this page and download the library: Download zv/zview library. Choose the download type require.
2. Extract the ZIP file and open the index.php.
3. Add this code to the index.php.
<?php
require_once('vendor/autoload.php');
/* Start to develop here. Best regards https://php-download.com/ */
<!--{if $a == $b && $b == 1}-->
a = b AND b = $b
<!--{elseif $b == 2 || $a == 3}-->
b = $b OR a = $a
<!--{elseif $a == 1}-->
a = 1
<!--{else}-->
a != 1
<!--{/if}-->