Combined animation does not repeat

I am trying to implement infinite pulsing animation. I try to do it like this for some View view:

var a = new Animation();
a.Add(0, 0.5, new Animation(f => view.Scale = f, 1, 1.2, Easing.Linear, null));
a.Add(0.5, 1, new Animation(f => view.Scale = f, 1.2, 1, Easing.Linear, null));
a.Commit(view, "ScaleTo", 16, 300, null, null, () => true);

The result is: it pulses only once, although animation is repeating (finished delegate in Commit function called repeatedly).
What have I done wrong? How to achieve the desired result?