Closure property We can say that rational numbers are closed under addition, subtraction and multiplication. For example: (7/6)+(2/5) = 47/30. (5/6) – (1/3) = 1/2.
Regular Languages are closed under intersection, i.e., if L1 and L2 are regular then L1 ∩ L2 is also regular. L1 and L2 are regular • L1 ∪ L2 is regular • Hence, L1 ∩ L2 = L1 ∪ L2 is regular.
Closure property for Integers Closure property holds for addition, subtraction and multiplication of integers. Closure property of integers under addition: The sum of any two integers will always be an integer, i.e. if a and b are any two integers, a + b will be an integer.
Closure under Union For any regular languages L and M, then L ∪ M is regular. Proof: Since L and M are regular, they have regular expressions, say: Let L = L(E) and M = L(F). Then L ∪ M = L(E + F) by the definition of the + operator.
Closure Properties of Regular Languages Given a set, a closure property of the set is an operation that when applied to members of the set always returns as its answer a member of that set. For example, the set of integers is closed under addition.
The closure property of addition states that when any two elements of a set are added, their sum will also be present in that set. The closure property formula for addition for a given set S is: ∀ a, b ∈ S ⇒ a + b ∈ S.
The closure property of rational numbers with respect to addition states that when any two rational numbers are added, the result of all will also be a rational number. For example, consider two rational numbers 1/3 and 1/4, their sum is 1/3 + 1/4 = (4 + 3)/12 = 7/12, 7/12 is a rational number.
Closure Property under Multiplication Real numbers are closed when they are multiplied because the product of two real numbers is always a real number. Natural numbers, whole numbers, integers, and rational numbers all have the closure property of multiplication.
Regular Languages are closed under intersection, i.e., if L1 and L2 are regular then L1 ∩ L2 is also regular. L1 and L2 are regular • L1 ∪ L2 is regular • Hence, L1 ∩ L2 = L1 ∪ L2 is regular.
The set of regular languages is closed under complementation. The complement of language L, written L, is all strings not in L but with the same alphabet. The statement says that if L is a regular lan- guage, then so is L. To see this fact, take deterministic FA for L and interchange the accept and reject states.