An Introduction to Functional Programming Through Lambda Calculus

- 108 -(add(mult zero ten)(digit_value ’9’))ten)(digit_value ’8’))"7") -> ... ->MAKE_NUMB (string_val (add(mult(add(mult(add(mult zero ten)(digit_value ’9’))ten)(digit_value ’8’))ten)(digit_value ’7’))"") -> ... ->MAKE_NUMB (add(mult(add(mult(add(mult zero ten)(digit_value ’9’))ten)(digit_value ’8’))ten)(digit_value ’7’))) -> ... ->MAKE_NUMB (add(mult(add(mult nine ten)(digit_value ’8’))ten)(digit_value ’7’))) -> ... ->MAKE_NUMB (add(mult ninety_eight ten)(digit_value ’7’))) -> ... ->MAKE_NUMB nine_hundred_and_eighty_seven => ... =>9876.13. Structure matching with listsWe have been defining list functions with a base case for an empty list argument and a recursion case for a non-emptylist argument, but we have translated them into explicit list selection. We will now extend our structure matchingnotation to lists and allow cases for the empty list NIL and for bound variable lists built with :: in place of boundvariables.