Write regular expressions for the following languages.1. the set of all alphabetic strings;2. the set of all lower case alphabetic strings ending in a b;3. the set of all strings from the alphabet a, b such that each a is immedi-ately preceded by and immediately followed by a b
Question
Write regular expressions for the following languages.1. the set of all alphabetic strings;2. the set of all lower case alphabetic strings ending in a b;3. the set of all strings from the alphabet a, b such that each a is immedi-ately preceded by and immediately followed by a b
Solution
- The regular expression for the set of all alphabetic strings is: [a-zA-Z]+
Explanation:
- [a-zA-Z] matches any lowercase or uppercase alphabetic character.
-
- indicates that the previous character or group should appear one or more times.
- The regular expression for the set of all lowercase alphabetic strings ending in a 'b' is: [a-z]*b
Explanation:
- [a-z] matches any lowercase alphabetic character.
-
- indicates that the previous character or group should appear zero or more times.
- 'b' matches the literal character 'b' at the end of the string.
- The regular expression for the set of all strings from the alphabet 'a' and 'b' such that each 'a' is immediately preceded by and immediately followed by a 'b' is: b(ab)*b
Explanation:
- 'b' matches the literal character 'b'.
- (ab) matches the sequence of characters 'ab'.
-
- indicates that the previous character or group should appear zero or more times.
- The expression b(ab)*b ensures that each 'a' is surrounded by 'b' characters.
Similar Questions
For each of the following languages over the alphabet Σ = {a, b, c} specified by the regular expressions (a)–(c),provide two strings in Σ∗ that are members and two strings in Σ∗ that are not members of the language (fourstrings each).(a) ab + a(b) ((bc)∗ + b)a(c) (a + ab + abc)∗(b + c)
Give the regular set for each of the following regular expressionsi. (10)*10*ii. a*U(bc*)iii. (0 U 1) (0 U 1)*00iv. a(bc)* U (dc)*v. (a U b . c)*vi. a.(b u c)vii. a* . (b u c)viii. (10)*10
Which of the following languages are regular?A = {x | x has two 0’s separated by the number of positions that is a multiple of 4 }.B = {x | x is binary representation of multiple of 3}.C = {x | x is a binary string and decimal of any prefix of x is not of form 3m + 2, where m ≥ 0}.Select one:a. All of the mentioned.b. Only B and C. c. Only A.d. Only B.
Which of the following is a regular language?
Which regular grammar generates the language consisting of strings with zero or more occurrences of "a" followed by "b"?Options :S -> ab | aS | εS -> a | b | aSS -> ab | aSnone
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