Prolog will only help them academically it is also limited for logic constraints and semantic NLP based work. Prolog is not yet an industry friendly language so not yet practical in real-world. And, matlab also is an academic based tool unless they are doing a lot of scientific or quants based work they wouldn't really have much need for it. To start of they might want to pick up the 'Norvig' book and enter the world of AI get a grounding in all the areas. Understand some basic probability, statistics, databases, os, datastructures, and most likely an understanding and experience with a programming language. They need to be able to prove to themselves why AI techniques work and where they don't. Then look to specific areas like machine learning and NLP in further detail. In fact, the norvig book sources references after every chapter so they already have a lot of further reading available. There are a lot of reference material available for them over internet, books, journal papers for guidance. Don't just read the book try to build tools in a programming language then extrapolate 'meaningful' results. Did the learning algorithm actually learn as expected, if it didn't why was this the case, how could it be fixed.
