1. Use regular expressions to describe strings made up of the letters a and b that: a) contain an even number of b 's (note that 0 is an even number). b) contain an odd number of b's. 2. Consider the following grammar in BNF notation: S>::=01::=0::=11 Which of the following sentences are in the language generated by this grammar? For those that are in the language, show a possible derivation. For the others, explain why they cannot be generated using the rules of the grammar. a. 10101 b. 10110 c. 001010 Describe the language generated by this grammar using regular expressions. 3. a) Trace the table-driven LL(1) parse of the input x:=(ab)/3, similar to the example on slide 47. b) Construct the parse tree for the input given in point a