Move the slider to choose the value of μ between −0.2 and 0.2, and
click your mouse to select (x0,y0). You will see how (xn,yn) changes (click
your mouse, and empty circles will pop up).
There is a transcritical bifurcation at μ=0: for μ<0, the fixed point
(0,0) is stable, while (μ,μ) (the red moving dot) is unstable;
the stability of these two fixed points are exchanged, when μ passes zero.