What is up with Haskellers starting these irrelevant Lisp vs Haskell arguments? OP made no mention or implication that Lisp is better than Haskell. It's petty and counterproductive.
Also, I'm not a "Haskeller". I do program in Haskell occasionally, though. I'm actually, at this time, a professional Common Lisp programmer.
I also wanted to provide Haskell as a kind of system which provides an inference engine that is much stronger than Lisp's. I don't want anyone to get the idea that Lisp implementations' inference engines is even commensurable to what exists elsewhere.