• S = 1, R = 0: Set
• S = 0, R = 0: Hold
• S = 0, R = 1: Reset
• S = 1, R = 1: Not allowed

$$ \begin{aligned} \sum_{n=1}^{\infty} a_n z^n &= \sum_{n=1}^{\infty} a_n z^n\\ &= \sum_{k=0}^{\infty} c_k (x-a)^k .\end{aligned} $$