GrammarGrammars are a Language-generation method based on rewritingIn my think, TM grammar is change of CFG which can even delete symbols not only addAutomaton Grammar NotionRegular ExpressionState Transition Table What is packrat parsing?At a high level: Packrat parsers make use of parsing expression grammars (PEGs) rather than traditional context-free grammars (CFGs). Through their use of PEGs rather than CFGs, it's typically easier to set up and maintain a packrat parser than a traditional LR parser.https://stackoverflow.com/questions/1410477/what-is-packrat-parsing