Exercise 3.16 [ Extend the language so that a let declaration can declare an arbi trary number of variables, using the grammar Expression- let [Identifier - Expressiony* in Expression As in Scheme's let, each of the right-hand sides is evaluated in the current environ ment, and the body is evaluated with each new variable bound to the value of its associated right-hand side. For example, let x 30 in let x = -(x, 1) y = -(x, 2) in - (x,y) should evaluate to 1 Exercise 3.16 [ Extend the language so that a let declaration can declare an arbi trary number of variables, using the grammar Expression- let [Identifier - Expressiony* in Expression As in Scheme's let, each of the right-hand sides is evaluated in the current environ ment, and the body is evaluated with each new variable bound to the value of its associated right-hand side. For example, let x 30 in let x = -(x, 1) y = -(x, 2) in - (x,y) should evaluate to 1