These complete projects are far too complex to represent completely here. We hope readers of this book will share their solutions with each other on the Internet. Try a search on the Web for the phrase "Perl Alpaca book LPORM answers." You can also use that phrase on the web page where you offer your solutions for downloading. To help anyone who finds your page, include links from your page to any other solutions that look interesting to you.
We search the Web from time to time, and so we may visit your site and look at your results. If we especially like your solution to the halting problem, we'll be sure to let you know.