I have many Prolog books and by far the most practical or "real world" of them is "Prolog Programming in Depth" by Covington/Nute/Vellino, which the lead author

I have many Prolog books and by far the most practical or "real world" of them is "Prolog Programming in Depth" by Covington/Nute/Vellino, which the lead author has made freely available as a PDF: http://www.covingtoninnovations.com/books/PPID.pdf http://www.covingtoninnovations.com/books/PPID.pdf It doesn't shy away from explicitly discussing how one goes about expressing various procedural/imperative constructs in a declarative manner.