Multiple tax terms by AND
$tax_query = array( array( 'taxonomy' => 'mytax', 'terms' => array( 'Term 1', 'Term 2' ), 'field' => 'name', 'operator' => 'AND', 'include_children' => false, ), );
$tax_query = array( array( 'taxonomy' => 'mytax', 'terms' => array( 'Term 1', 'Term 2' ), 'field' => 'name', 'operator' => 'AND', 'include_children' => false, ), );