The minimal supported PHP version is 7.0.
In 2.x, you were able to create an Abac instance the following way:
<?php
use PhpAbac\Abac;
$abac = new Abac($configurationFiles, $cacheOptions);
Today, the Abac class constructor has dependencies as arguments:
<?php
use PhpAbac\Abac;
$abac = new Abac($policyRuleManager, $attributeManager, $comparisonManager, $cacheManager);
To make life easier, a factory pattern was implemented. If you're not interested in replacing default dependencies, you can simply use:
<?php
use PhpAbac\AbacFactory;
$abac = AbacFactory::getAbac();