Verification: Explain manual analysis

[amyjko]

I was hoping for more information about manual analysis.  In the example, there was a paragraph written about a manual analysis of the JavaScript code.  I am having a hard time finding the benefits of manual analysis because it seems so easy for someone to miss something.  What if someone forgot about negative integers?  Are there any tips or a recommended way to go about manual analysis? Also, I really like how up-to-date and current and clear this book is.  I usually have a hard time staying focused during required readings but these are my favorite.