Create context$-$free grammars that generate the following languages.

a$.L_3=a^n{b}^{m^n},($n$,m1)$

b$.)$

$G=(V,{\displaystyle \underset{?}{\overset{?}{}}},R,S)$ grammar is defined as follows:

$V=\{S,A,a,b\},$

$=\{a,b\}$ and

$R=\{S$aAa,$Se,S$bAb,$ASS\}$

Examine the above context$-$free grammar and create parse trees for the given strings

a$.$ bb

b$.$ baabbb

c$.$ abaabaabbbbbba