def tail = { jjj ->
        println jjj

        return <selection>fact</selection>(jjj)
}

int fact(int n) {
        if (n > 0) {
                return n * fact(n - 1)
        }
        return 1
}
-----
def tail = { jjj ->
    println jjj

    if (jjj > 0) {
        return jjj * fact(jjj - 1)
    }
    return 1
}

int fact(int n) {
        if (n > 0) {
                return n * fact(n - 1)
        }
        return 1
}