Why do you backtrack when you hit a book?

Btw, people often cite the earliest articles, but not necessarily the simplest.

Often there are papers like '[topic] simplified' etc, and they can be quite useful.

In our case, an alternative approach is to just do a web search for 'how to write a simple sat solver' and that yields eg https://www.gibiansky.com/blog/verification/writing-a-sat-so... and https://sahandsaba.com/understanding-sat-by-implementing-a-s...