Consider the grammar: S → AB | C A → aAb | ab B → cBd | cd C → aCd | aDd D → bDc | bc Show in particular that the string aa bb cc dd: (i) Parse tree; (ii) Leftmost derivation; (iii) Right most derivation; (iv) Is the grammar is ambiguous or not?

The string aa bb cc dd has two left most derivation and the two parse left most derivation and the two parse tree:
(i&ii)
S ⇒ AB
L.M.D
→ aAbB
→ aabbB
→ aabb CBd
→ aabb CCdd
Parse tree →

And,
S ⇒ C
L.M.D
→ aCd
→ aaDdd
→ aab Dcdd
→ aabbcdd
Parse tree →

(iii) Right most derivation:
S ⇒ AB
R.M.D
→ AcBd
→ Accdd
→ aAb ccdd
→ aabb ccdd
(iv) Yes, the grammar is ambiguous.