[Haskell-cafe] how do you debug programs?

Hi, I would like to learn a reasonable way (ie how others do it) to debug programs in Haskell. Is it possible to "see" what's going on when a function is evaluated? Eg in f a b = let c = a+b d = a*b in c+d evaluating f 1 2 would output something like f called with values 1 2 c is now (+) a b => (+) 1 2 => 3 d is now (*) a b => (*) 1 2 => 2 ... Or maybe I am thinking the wrong way, and functional programming has its own debugging style... Thanks, Tamas