**Examples of Infinite Regular Expressions**

Infinite Regular expressions are used to represent the infinite regular languages. So, the length of infinite regular expressions is always Unlimited.

**Example 01**

Write the regular expression for the language which accepting all the strings which having all combinations of a’s over ∑ = {a}.

**Solution**

Language for given example is given below

L = { ε, a, aa, aaa, aaaa, aaaaa, ……….. }

Regular expression for above language is given below

L(R) = a*

**Example 02**

Write the regular expression for the language which accepting all the strings which having all combinations of a’s except the null string over ∑ = {a}.

**Solution**

Language for given example is given below

L = {a, aa, aaa, aaaa, aaaaa, ……….. }

Regular expression for above language is given below

L(R) = a

^{+}

**Example 03**

Write the regular expression for the language which accepting all the strings, which **having **any number of a’s and b’s **over** ∑ = {a, b}.

**Solution**

Language for given example is given below

L = {a, b, ab, ba, aab, aba, aaba ……….. }

Regular expression for above language is given below

L(R) = (a+b)*

**Example 04**

Write the regular expression for the language which accepting all the strings, **having only one “b” and any numbers of “a” over** ∑ = {a, b}.

**Solution**

Language for given example is given below

L = {b, ab, aba, abaa, abaaaa, aaaaabaaaaaaa……….. } // all strings having only one “b”

Regular expression for above language is given below

L(R) = a*ba*

**Example 05**

Write the regular expression for the language which accepting all the strings, **which **are starting with 1 and ending with 0, over ∑ = {0, 1}.

**Solution**

Language for given example is given below

L = {10, 100, 11010, 1110, 1111000, ……….. } // starting with 1 and ending with 0

Regular expression for above language is given below

L(R) = 1(0+1)*0

**Example 06**

Write the regular expression for the language which accepting all the strings having even length, over ∑ = {0}.

**Solution**

Language for given example is given below

L = { ε, 00, 0000, 000000, 00000000, ……….. }

Regular expression for above language is given below

L(R) = (00)*