There is are a couple
<a href="http://www.learnprolognow.org/" rel="nofollow">http://www.learnprolognow.org/</a>
<a href="http://www.amzi.com/AdventureInProlog/advfrtop.htm" rel="nofollow">http://www.amzi.com/AdventureInProlog/advfrtop.htm</a><p>A good way is to look at maybe the lecture notes of an undergrad functional programming course. They usually present it quite simply.<p>Unfortunately the course at UBC does not post the lectures online openly but rather through a restricted CMS.