The cash registers at the Rice Epicurean Market talk to you. A register's controller receives a number greater than 0 and then builds a list with the following five elements:

1. the dollar amount;
2. the symbol 'dollar if the dollar amount is 1 and 'dollars otherwise;
3. the symbol 'and
4. the cent amount; and
5. the symbol 'cent if the cent amount is 1 and 'cents otherwise.

(cons 1 (cons 'dollar (cons 'and (cons 3 (cons 'cents empty)))))

You are to define the controller as a Scheme program. You may use our solution to Problem 2 of the first homework set.

Hints: Recall that Scheme provides the functions quotient and remainder.

Develop the program lookup. The program takes an symbol, which is called the search-key, and a table. It returns the first pair whose key is equal to the search-key. If it can't find such an pair, it returns false.

Note: Schemers often call such a table an A-list, short for association list.