For people interested on this topic I strongly recommend to also look at Ben Hanson https://github.com/BenHanson/parsertl17 and based on it I've created an online LALR(1) playground here https://mingodad.github.io/parsertl-playground/playground/ where you have around 350 non trivial. grammars to experiment (select one from the `Examples` dropdown and then click `Parse` to see a parse tree for the input in `Input`, it also generates EBNF to generate nice navigable railroad diagrams on https://www.bottlecaps.de/rr/ui .