Uniqueness theorem

Statement

For domains in the complex numbers

Suppose $U$ is a nonempty domain (open connected subset) of $\mathbb {C}$. Then, given two maps $f,g:U\to \mathbb {C}$, exactly one of these two possibilities holds:

• $f\equiv g$ on $U$
• The set of points $z$ for which $f(z)=g(z)$ is a discrete closed subset (i.e. it has no limit points)

For Riemann surfaces

Fill this in later