'PHP version',
		'mandatory' => true,
		'condition' => version_compare(PHP_VERSION, '5.4.0', '>='),
		'by' => 'Yii Framework',
		'memo' => 'PHP 5.4.0 or higher is required.',
	),
	array(
		'name' => 'Reflection extension',
		'mandatory' => true,
		'condition' => class_exists('Reflection', false),
		'by' => 'Yii Framework',
	),
	array(
		'name' => 'PCRE extension',
		'mandatory' => true,
		'condition' => extension_loaded('pcre'),
		'by' => 'Yii Framework',
	),
	array(
		'name' => 'SPL extension',
		'mandatory' => true,
		'condition' => extension_loaded('SPL'),
		'by' => 'Yii Framework',
	),
	array(
		'name' => 'MBString extension',
		'mandatory' => true,
		'condition' => extension_loaded('mbstring'),
		'by' => 'Multibyte string processing',
		'memo' => 'Required for multibyte encoding string processing.'
	),
	array(
		'name' => 'Intl extension',
		'mandatory' => false,
		'condition' => $this->checkPhpExtensionVersion('intl', '1.0.2', '>='),
		'by' => 'Internationalization support',
		'memo' => 'PHP Intl extension 1.0.2 or higher is required when you want to use advanced parameters formatting
		in Yii::t(), IDN-feature of
		EmailValidator or UrlValidator or the yii\i18n\Formatter class.'
	),
);