What language is generated by the following grammars? In each case justify your answer.
- $S\rightarrow 0S1 \mid 01$
- $S\rightarrow +SS \mid -SS \mid a$
- $S\rightarrow S(S)S \mid \epsilon$
- $S\rightarrow aSbS \mid bSaS \mid \epsilon$
- $S\rightarrow a \mid S+S \mid SS \mid S^{\ast} \mid (S)$