Each of these questions illustrates different Prolog concepts and the suggested solutions include notes to further explain any new concepts.

It would be worthwhile entering the source code within each question into Prolog and testing to confirm the answers and reinforce the ideas within your own mind. 

You cannot learn a programming language by reading a book so it is also important to learn to develop Prolog source code for some simple problems yourself.

Rather than continuing to explain the syntax and operation of Prolog in further detail a number of example HSC style questions have been reproduced below.