alaaalawi

or allow returning multiple values. for example in CL searching for a thing returns two values the is-found and the value

I second the suggestion "Foundation of Computer Science" the full book is available as pdf. its language is clear. it uses C langauge. there is another edition using Pascal (which I have and IMHO is better even when learning about data structures involving memory references). you may also find a dirt cheap used copy.

or 355 / 113. I memorized 113355. good enough for a lot. initially got it from https://colorforth.github.io/pi.htm