[see also: aid
This will help us find what conditions on A are needed for T(A) to be analytic. [Or: help us to find]
The knowledge of the invariant subspaces of an operator helps us to visualize its action.
It is hoped that a deeper understanding of these residues will help establish new results about the distribution of modular symbols.
To calculate (2), it helps to visualize the Sn as the successive positions in a random walk.