April 28th, 2014, 12:23 am
Doesn't XOR have a fixed point because XOR(x,x) = 0? And if you do x[n] = XOR(x[n-1],y), doesn't it drop into a 2-cycle, in general, and a fixed point for some bit patterns?For x[0] = 0011, y = 1010, the sequence is 1001, 0011, 1001