Let $D$ be a divisor and $V$ a vectorial subspace of $L(D)$. The set of the divisors $S=\{(f)+D\mid f\in V\}$ is called a linear system. A point $P\in C$ is a base point if for every divisor $D\in S$, we have $P\in D$.
I'm looking for easy examples of linear systems without base points. This will help me to see this abstract definition in a more concrete way.
Thanks