🌐EnglishEnglishDeutschEspañolFrançaisItalianoNederlandsPolskiPortuguêsРусскийفارسی日本語EntityQ2596624· pop 14· linked from 23 articlesPumping lemma for context-free languageslemma giving a property shared by all context-free languagesConnectionsformal languageEntityreductio ad absurdumEntityCategoriesFormal languagesLemmas