Chapter $3.$ Exercise $1.$a

Start with the grammar G$6,$ repeated here:

Modify it to include subtraction and division operators $(-$ and $/)$ with the customary precedence and associativity.

$2.$ Chapter $3.$ Exercise $3.$a

Show that the following grammar is ambiguous. $($To show that a grammar is ambiguous, you must demonstrate that it can generate two parse trees for the same string.$)$

G$4$: