var factorial = [n | if (n < 2) [1] [factorial (n-1) * n]];

var for_all_permutations = [array fun |
	var iter = [start stop x | if (start >= stop) [x] [iter (start+1) stop (fun x)]];
	iter 0 (factorial (len array)) array
];

for_all_permutations (flat 1 2 3 4 5) [array|
	say array;
	permute array
];