Integer division in CO always rounds its result towards zero. In particular -9/2 is equal to -4. In other languages instead, the division always rounds towards infinite. In this case, -9 divided by 2 is equal to -5. In this case the division is called the quotient and the associated modulus is called remainder. Let's suppose we want to implement this convention: you need to write two CO functions quotient and remainder with the following property: quotient(x,y)*y + remainder(x,y) == x; for all ints x and y unless quot overflows. Put the correspondig contracts in a file, and test them in Coin.