The source files are tut11.tv, and mac1.v or mac1.vhd. tut11.tv is simply a safer version of tut10.tv; it enforces strict size checking on module ports, and requires various correctly-sized variables to be declared. The output should be identical to that from Exercise 13.
tut11.tv contains the first use of the for all statement. for all is equivalent to the standard for loop, but simplifies iterating over all values of a 'small' data type.