compose_i(,,)
{
    ($0)(($1)($2));
}

compose(,)
{
    compose_i.apply($0, $1);
}

double(real a)
{
    2 * a;
}

square(real a)
{
    a * a;
}

main(void)
{
    o_(compose(square, double)(40), "\n");

    0;
}