Question

Write a regular expression (or definition) for each of the following languages. For each case, specify the input alphabet as well.
(a) Strings over the alphabet {a,b,c} where the first a precedes the first b
(b) Comments consisting of a string surrounded by /* and */
(c) All strings of 0’s and 1’s with an even number of 0’s , with at least two 0’s.
(d) {w ∈{a,b}*|w starts with a and contains bba as a substring }
(e) {w ∈{0,1}*|w contains 111000 as a substring } (f) {w ∈{0,1}*|w consists of alternating 0’s and 1’s }