To use Haskell from a shell, you need to add /cse/courses/misc_lang/axp/hugs-1.4/bin to your path (in your .cshrc file). Now you can type hugs at the shell to get the Haskell interpreter.
Click on the Start button, and choose the Programs menu. From there, select the Server Apps menu, and finally select Hugs 1.4. To use the Haskell interpreter as you would from a shell, choose the Hugs option.
You can download and install Hugs 1.4 yourself here.
Unlike with Scheme and SML, you cannot define functions directly into the Hugs interpreter, but can only evaluate expressions. Instead you must load a file containing the function(s) you want. When running Hugs, you can load the contents of a file by typing :load "file.hs".
To quit the Hugs interpreter, type :quit.