visualization of step validation; 271 steps to address

I created a page listing all the steps from every derivation. The utility is that I can summarize how many steps are valid (180 out of 638, or 28%), how many are declarations and assumptions (179+8, or 29%), and how many fail or are not checked -- the remaining 40%.

My plan is to work on addressing the
638-(180+179+8)=271 
failed or unchecked expressions.

I expect SymPy doesn't support all the inference rules, so I need a way to categorize that issue.