System.out.println(f.apply(a,b));
DoubleDoubleFunction g = new DoubleDoubleFunction() {
public final double apply(double x, double y) { return Math.sin(x) + Math.pow(Math.cos(y),2); }
};
System.out.println(g.apply(a,b));
DoubleFunction m = F.plus(3);
DoubleFunction n = F.plus(4);
System.out.println(m.apply(0));
System.out.println(n.apply(0));
}