Nested Meta

$meta_query = array(
	'relation' => 'AND',
	array(
		'relation' => 'AND',
		array(
			'key'     => 'age',
			'value'   => '10',
			'compare' => '>',
			'type'    => 'NUMERIC',
		),
		array(
			'key'     => 'age',
			'value'   => '20',
			'compare' => '<',
			'type'    => 'NUMERIC',
		),
	),
	array(
		'key'     => 'gender',
		'value'   => 'male',
		'compare' => '=',
		'type'    => 'CHAR',
	),
);