Proof:
Closure properties: Intersection
• Let L1, L2 be two regular languages
• L1, L2 are regular languages
(the family of regular languages is closed under complement)
• L1 È L2 is a regular language
(the family of regular languages is closed under union)
• L1 È L2 is a regular language
(the family of regular languages is closed under complement)
• L1 Ç L2 = L1 È L2 is a regular language (DeMorgan’s law)
Theorem: The family of regular languages is closed under intersection.
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