Here is the recommended approach for project $4.$

$1)$ Although you have the option of keeping the interpreter from project $3$ in the final project, it is

a more complicated approach. Unless you are an experienced C$++$ programmer, it will be

simpler to take your project $2$ implementation and begin by incorporating what is in the project $4$

skeleton, much like what you should have done for project $3.$ Because your project $2$ has

additional productions, be sure to include them in your $\%$type declaration. You are likely to have

some type clash warnings at this point. You initially should be able to ignore them. Once you

complete the project, they should all be resolved, however.