1. Find an S-grammar for L = {aN+ bN: N 1} L2 = {aaba+bb} 2. Find a context-free grammar for the following language with n 1, m 1, k 1. L3= {a" b c m=n+k } (2 points) (1 point) (2 points) 3. Take out all undesirable production forms from the following production rules. According to the orders show all of your works! SaA B AaA aB | B Bb bb C Cb (a) Remove -productions (b) Remove Unit-productions (c) Remove Useless productions. = {a, b} (3 points) 4. Show that the following grammar is ambiguous. (2 point) SaA | A AaAb a ab = {a, b}