This subject is treated at length in Section 2.
See also , where functions of exponential type are the main subject.
We cannot survey this whole subject here.
It seems that the relations between these concepts emerge most clearly when the setting is quite abstract, and this (rather than a desire for mere generality) motivates our approach to the subject.
Choose $f$ in $G$ subject only to the condition that $Lf=0$.
They established the Hasse principle subject to a rank condition on the coefficients.
Take $ N$ to be a family of normal measures in $P(X)$ such that $ N$ is maximal subject to the condition that the supports of the measures in the family are pairwise disjoint.
The location of the zeros of a holomorphic function in a region $\Omega$ is subject to no restriction except the obvious one concerning the absence of limit points in $\Omega$.