--TEST-- Check subset size equal to zero --FILE-- <?php require_once 'Math/Combinatorics.php'; $combinatorics = new Math_Combinatorics; var_dump($combinatorics->combinations(array('a','b'), 0)); var_dump($combinatorics->permutations(array('a','b'), 0)); ?> --EXPECT-- array(0) { } array(0) { }