3. Are the following languages A and B over the alphabet ={a,b,c,d} regular or nonregular? - For a language that is regular, give a regular expression that defines it. - For a nonregular language, using the pumping lemma prove that it is not regular. (a) (2 marks) A={ajbk+2cm+1j1,k1,m1}{brcs+2dt+1rt1,s1} (b) (2 marks) B={aj+3b2k+2cmj1,k1,m1}{br+3csd2t1r1,s1,t1} Hints: The languages A and B are each expressed as a union of two sets. If one (or both) of the sets is non-regular, this does not imply anything about the non-regularity of the union. When trying to show that a language C is non-regular, we have to apply the pumping lemma to the entire language C (and not to the components of the union). On the other hand, if trying to show that C is regular, you can give regular expressions for the two component sets and then apply "+