So I am studying this great book, and Chapter $3.1$ is about registers.
Quoting from this book / chapter:
A register is a storage device that can "store" or "remember" a value over time, implementing the classical storage behaviour $out(t) = out(t-1)$.
What is mean by:
the classical storage behaviour $out(t) = out(t-1)$ ?
If $out(2) = out(1)$ and $out(1) = out(0)$ how are we ever going to store a value?