Define a BNF grammar that generates each of the languages

a$.\{a^n{b}^m|nm>0\}$ that is the number of b$\text{'}$s can be $1,2,$dots and number of a$\text{'}$s can be equal to the number of b$\text{'}$s or greater, but not less. The a$\text{'}$s come at the beginning of the string and b$\text{'}$s come at the end. NOTE: this is similar to problem #$1$ but in problem #$1m0$ and in this problem $m>0.$

b$.|0$ and $\{$:$m=n+1\}$ that the number of a$\text{'}$s onn be $0,1,2,$dots and there is one more $b$ than a$\text{'}$s

c$.$ Let $$ be the alphabet consisting of the four symbols $(,),[,$ and $].$ Let $L$ be the language over $$ consisting of strings in which both parentheses and brackets are balanced. For example, the string $([][()()])([])$ is in L but $[(])$ is not. Find a context$-$free grammar that generates the language $L$