import math

function compose (f, g) {
    return function (x) { return f(g(x)) }
}

var fn  = [Math.sin, Math.cos, function(x) { return x*x*x }]
var inv = [Math.asin, Math.acos, function(x) { return Math.pow(x, 1.0/3) }]

for (var i=0; i<3; i++) {
    var f = compose(inv[i], fn[i])
    println(f(0.5))    // 0.5
}