I was trying to convert a function, f1 x l = map (\y -> y*x) l to so-called point-free style, but in reducing it I found two functions that seemed to work the same, until I discovered they have different types, and aren't equivalent: f1a x = map (*x) -- has type (Num a) => a -> [a] -> [a] f1b = \x -> map (*x) -- has type Integer -> [Integer] -> [Integer] Can someone help me understand why the latter has a more restrictive type? If I add the type signature "f1b :: (Num a) => a -> [a] -> [a]", they are once again equivalent, but am confused about what's going on. If this is MR, what exactly am I overloading here? I read through http://www.haskell.org/haskellwiki/Monomorphism_restriction and http://www.cs.auckland.ac.nz/references/haskell/haskell-intro-html/pitfalls..... If anyone has a good reading recommendation here, I'd love to see it. Because if this is MR, I'm not understanding what MR is correctly. Also, They don't generate a type error, which makes me think it is not MR, but something else. Thanks, Mike