# Need help in finding the sources to read some formulas related to information theory [closed]

I am reading an article. I have not read information information theory before. Can some one please tell which results are used in equation $$(34)$$ and what result is used to arrive at the conclusion that $$I(R; qBf_S^{*}|qBf_S)=H(R)$$

I am not able to find a exact source from where I can look into these formulas.

• Equation (34) is simply the chain rule for conditional mutual information, you can find it in the Wikipedia page, it's the second identity in the section "Some identities". I'm not sure about the other result but you should be able to get it after some manipulations with the formula in the Wikipedia. Anyway this is a math question and I think it will do better in math.se :) – user2723984 Mar 10 at 15:48

## 1 Answer

The books on information theory are plenty - you could find lots of them by googling, searching on amazon, or searching in this site (for example, here).

From my personal experience, Elements of information theory by Cover and Thomas is pretty accessible to somebody with physics background. Another excellent source is the Shannon's original paper - it is old, but very clearly written, and may also provide a useful first step into the algorithms used in language processing and bioinformatics.