a.gear

fn a [2, b] { alert(a)
            ; alert(b) }

b.js

(function () {
    var __gear0 = arguments;
    if (__gear0.length !== 2) {
        throw new Error('bad pattern');
    }
    var a = (__gear0)[0];
    var __gear1 = (__gear0)[1];
    if (__gear1.length !== 2) {
        throw new Error('bad pattern');
    }
    if (((__gear1)[0]) !== 2) {
        throw new Error('bad pattern');
    }
    var b = (__gear1)[1];
    return (function () {
        (alert)(a);
        return (alert)(b);
    })();
});