Closure and Decision Properties of Regular Languages
Combine two regular languages almost any way you like and the result is still regular, and that fact is a tool for proofs.
What this unit covers
Unit 3: Regular Expressions and Regular Languages
- 1 Regular Expressions and Regular SetsA one-line pattern that names a whole infinite language, and the algebra that lets you simplify it. · 12 min
- 2 Conversion of Regular Expressions to Finite AutomataSnap together tiny machines like Lego bricks, one per symbol and one per operator, and the whole pattern becomes an automaton. · 12 min
- 3 Conversion of Finite Automata to Regular ExpressionsRemove the states one by one, writing what each one did onto the arrows, until only the pattern is left. · 13 min
- 4 The Pumping Lemma for Regular LanguagesA machine with p rooms that walks p steps must enter some room twice, and that one fact proves which languages no automaton can recognise. · 14 min
- 5 Closure and Decision Properties of Regular LanguagesCombine two regular languages almost any way you like and the result is still regular, and that fact is a tool for proofs. · 13 min