hi, it's probably very trivial but i still don't get it: a multi-dimensional array like $a=array(1 => array ( 2 => array ( 3 => array( "3A" => array( "3B" => array( "X" => array() ), "3C" => array( "X" => array() ) ) ), 4 => array( 5 => array( "X" => array() ), "5A" => array( 6 => array( "X" => array() ) ) ) ), ) ); shall be converted to one-dimensional arrays containing a path from 1 to X, in the given example four arrays: 1: array(1, 2, 3, 3A, 3B, X) 2: array(1, 2, 3, 3A, 3C, X) 3: array(1, 2, 4, 5, X) 4: array(1, 2, 4, 5A, 6, X) any help appreciated!