$$ \begin{array}{111|1} \text { Given a CFG } G=(V, T, S, P) & \text { (a) Give a string and draw its two } | \text { where } V=\{S, A, B, C, DV}, T=\{a, b, c\} & \text { parse trees to show that } G \text { is ambiguous. } \text { and } P \text { is defined as follows: } & \text { (b) Remove ambiguity from } GW S & ightarrow AIS SI \lambda A & ightarrow B DID CIDDW B & ightarrow b BlBa| \lambda C & ightarrow a CICCI \lambda D & ightarrow D D \mid a \end{array} $$ CS.VS. 1008