The Pumping Lemma - A property of Regular Languages скачать в хорошем качестве

The Pumping Lemma - A property of Regular Languages

Checking expressions with brackets requires counting of left and right brackets. Similarly, checking words from a^nb^n requires counting of the as and bs. Finite Automata do not have external memory for such counting and can only use its states as memory. For long input strings, the memory is eventually exhausted and the automaton cannot distinguish precisely long input strings. The automaton must have loops. Such loops can then be used multiple times. Long strings can therefore be "pumped". This idea is formalised in the pumping lemma. It states a property that every regular language has. Therefore, if a language does not have this, we can conclude that the language is not regular.