var f1 = function (x) { return [1, x]; };
var f2 = function (x) { return [2, x]; };
var f3 = function (x) { return [3, x]; };
alert( repr(f1(f2(f3(4)))));
alert( repr(compose(f1,f2,f3)(4)));
alert( repr(compose(compose(f1,f2),f3)(4)));
alert( repr(compose(f1,compose(f2,f3))(4)));