The language is a term rewriting language. https://reference.wolfram.com/language/tutorial/Evaluation.html https://reference.wolfram.com/language/tutorial/Evalu

The language is a term rewriting language. https://reference.wolfram.com/language/tutorial/Evaluation.html https://reference.wolfram.com/language/tutorial/Evaluation.h... covers most of the evaluation process. The documentation for functions lists out the different forms they expect. Lisp-style macros are actually difficult to write because of the infinite evaluation of the language. I was able to write a quasiquote package for myself to help with that that though.