Write an SDD for a CFG that generates the language $\{a,b{\}}^{**}$ such that the start variable has

an attribute check whose value is $1$ if the generated string is of the form $uv$ where $|u|=|v|$

and the number of as in $u$ is strictly greater than the number of as in $v.$ Otherwise, the value

of Check is $0.$

In constructing the SDD$,$ make sure that the only operations performed on attributes are assi$-$

gnments, additions, subtractions, multiplications, and equality checks; an equality check is an

expression of the form $x==y$ whose value is $1$ if $x$ is equal to $y$ and is $0$ otherwise. $($Note

that inequality checks are not allowed.$)$