5. (6 marks) Let 2 = {a,b,c,d}. Give context-free grammars that generate the following languages. In each case, also give a derivation of the specified terminal string using your grammar. The derivation beginning from the start variable should indicate each individual derivation step using the notation (c) L3 = {a?"b3i+1c38+10+1 | i > 1,7 > 1,8 > 1} Derivation for the string: a4b4c7d