Set starts several animations
With a click on a circle the xlink:href attribute
of the a element around the circle is changed with
a set animation. The begin of this set animation
starts an animate animation, which depends on
the changed content of the xlink:href attribute:
First click - horizontal movement.
Second click - vertical movement.
Third click - changes the size of the circle.
Note, that activation with hyperlinks resolves
begin times, therefore later activation gives
access to the history of the animation with the
latest resolved begin times for all elements.