CSE322 PROPERTIES OF REGULAR LANGUAGES Lecture #12
Closure properties of Regular set Set Union Concatenation Closure(iteration) Transpose Set intersection Complementation
Properties of Regular Languages
For regular languages and we will prove that: Union: Are regular Languages Concatenation: Star: Reversal: Complement: Intersection:
Union: Concatenation: Star: Reversal: Complement: Intersection: We say: Regular languages are closed under Union: Concatenation: Star: Reversal: Complement: Intersection:
Regular language Regular language NFA NFA Single aceepting state Single accepting state NFA
Example
Union NFA for
Example NFA for
Concatenation NFA for
Example NFA for
Star Operation NFA for
Example NFA for
Reverse NFA for Homework 2
Complement Homework 2
Intersection regular We show regular regular
DeMorgan’s Law: regular
Example regular regular regular
Construct a new FA that accepts Another Proof for Intersection Closure Machine Machine FA for FA for Construct a new FA that accepts simulates in parallel and
States in State in State in
FA FA transition transition FA transition
FA FA initial state initial state FA Initial state
FA FA accept state accept states FA accept states Both constituents must be accepting states
Example:
Automaton for intersection
simulates in parallel and accepts string if and only if accepts string and accepts string