Consider a system with transfer-function G(s) = 2/(s + 1). A unit step function u(t) is applied to the system, which results in an output y(t). If  \(\lim\limits_{t \to \infty} \) e(t) = y(t) − u(t), then \(​​​​\lim\limits_{t \to \infty} \)e(t)limt→∞⁡e(t)" role="presentation" style="display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;" tabindex="0">limt→∞e(t)$\underset{t\to \mathrm{\infty }}{lim}$