<?php require_once 'Math/Combinatorics.php'; $combinatorics = new Math_Combinatorics; $set = array( 'one' => 'a', 'two' => 'b', 'three' => 'c', 'four' => 'd', 'five' => 'e', 'six' => 'f', 'seven' => 'g', 'eight' => 'h', ); $combinations = $combinatorics->combinations($set, 3); $permutations = $combinatorics->permutations($set, 3); ?>