Q11

Consider the grammar $S \rightarrow bSe$ $S \rightarrow PQR$ $P \rightarrow bPc$ $P \rightarrow \varepsilon$ $Q \rightarrow cQd$ $Q \rightarrow \varepsilon$ $R \rightarrow dRe$ $R \rightarrow \varepsilon$ where $S, P, Q, R$ are non-terminal symbols with $S$ being the start symbol; $b, c, d, e$ are terminal symbols and ‘$\varepsilon$’ is the empty string. This grammar generates strings of the form $b^i, c^j, d^k, e^m$ for some $i, j, k, m \geq 0$.