An intelligent system is a system that autonomously gathers information accessible to it, learns how to use this information to achieve its terminal goal and uses this skill. Does your prolog "AI" fit this description? Does it "write" its own logic? If yes, then it is intelligent. If no, then it is no different than some random non intelligent computer program.
I mean, you can simply define something differently than the last 50 years of researchers in computer science. It's just not going to make a difference.