Consider the following matrices $A\in\mathbb{R}^{n\times n}$, $B\in\mathbb{R}^{n\times n}$, with $A=-A^\top$, $B=B^\top\leq0$.
From several analytical calculations it turns out that
$$ (A+B)^{-1}=C+D, $$
with $C=-C^\top, D=D^\top\leq0$.
- Can anyone provide a proof for this to hold for any n?
- Is there any analytical formulation for the matrices C and D?
EDIT: If this is of some relevance or help in proof, I might be interested also in the case that B is strictly negative.
Thanks for your help.