Question

Describe the following sets as regular expression.

1. {0,1,2,3}
2. {^, ab}
3. {xyz, x, y, xy, yz, z, xxzz}
4. {^, 1,11,111,1111, .....}
5. {0,00,000,.....}

Answer 1

Sets can be represented by regular expressions that match the patterns within them. The given sets correspond to the regex patterns [0-3], (ab)?, (x?y?z?|xyz|xxzz), 1*, and 0* respectively.

Step-by-step explanation:

To describe the following sets as regular expressions:

1. {0,1,2,3} can be described by the regular expression [0-3].
2. {^, ab} where ^ represents the empty string, can be described by the regular expression (ab)?.
3. {xyz, x, y, xy, yz, z, xxzz} is a bit more complex, but you can capture most of the patterns using (x?y?z?|xyz|xxzz).
4. {^, 1,11,111,1111, ....} where sequences of one or more '1's are included (as well as the empty string), can be described by the regular expression 1*.
5. {0,00,000,.....} contains sequences of zeros, which can be described by the regular expression 0*.