An operator T which maps a
Banach space X into itself has the single valued extension property if the only
analytic function f which satisfies (λI − T)f(λ) = 0 is f = 0. Clearly the point
spectrum of any operator which does not have the single valued extension property
must have nonempty interior. The converse does not hold. However, it is
shown below that if λ0I − T is semi-Fredholm and λ0 is an interior point of
the point spectrum of T, then T does not have the single valued extension
property.