z has so far output [1; 1, 2, 7] = 1 + 1/(1 + 1/(2 + 1/7))
= 1 + 1/(1 + 7/15)
= 1 + 15/22
= 37/22
This is indeed the correct answer (we were computing 13/11 + 1/2, remember)
What if we ask z for another term?
It knows that its own value is 1/0 =
So it reports that it has no more terms left