Global: Spell-check paper
Theory, OOS convergence: Tweak spacing in equation
Theory, OOS convergence: break down and make strong assumption

This commit adds additional restrictions on the eigenvalues of the
conditional expectation of X'ee'X that are needed to prove Lemma 2.
The commit also makes the changes to Lemma 2's proof, so it should
hold now.
Assumptions: add short text after eigenvalue asmp
Theory: first draft of how assumptions are satisfied in example