Prelude.hs?

I have just built and installed Hugs 6.6 on AMD 64-bit OpenBSD 3.9. It seems to work ok, but I just discovered that the function primMinInt mentioned on page 13 of _The Haskell Road to Logic, Maths and Programming_ is not recognized. I also do not get 'Prelude>' as the prompt when I invoke hugs. I get 'Hugs>' instead. How do I get primMinInt to work? Thanks, Dave Feustel