ɸ, λ, a ∊ ∑ is a regular expression (primitive R.E)
are regular expression then,
Some examples of regular expression:
1. L = set of all strings terminated by either a or bb.
Regular Expression = (a + b)* (a + bb)
2. L = even no. of a’s followed by odd no. of b’s.
Regular Expression =
3. L = at least one pair of consecutive zero.
Regular Expression = (0 + 1)*00(0 + 1)*
4. L = set of all strings with no pair of consecutive zero.
Regular Expression = (01 + 1)*(0 + λ) or (0 + λ) (10 + 1)*