If there is a value which f(z) could be assigned at an isolated singular point which would make the function holomorphic at that point, then that point is termed a removable singularity. For example, if f(z) = 1/z, then |f(z)| → ∞ as |z| → 0, so this is not a removable singularity (but rather a pole), but for $f(z)=\frac{\text{sin}z}{z}$, which is undefined at z = 0, if we define f(0) = 1 the function is holomorphic at 0, and this is an example of a removable singularity. As a holomorphic function can be analytically continued to a removable singularity, many authors do not consider removable singularities to be genuine singularities.