[Haskell-beginners] Empty list and null

Why does Haskell so often seem to treat [] as a general null. For example I know 0 : 1 : [] gives [0, 1]. But shouldn't it produce a type fault in a consistent world? Int:Int:List isn't properly a list. It mixes types. I expect something like: Let GSN mean general_scalar_null. 1 : 2 : GSN -- works 1 : 2 : [] -- type fault, cannot mix int and empty list in the same list. And why does [] == [] : [] instead of [[], []] == [] : [] What sorts of nullity are there in core Haskell? Trent.