问题
Bottom in Haskell described here is said to be any computation that have errors, is unterminated, or involves infinite loop, is of any type... is this specific to Haskell? We know in Lattice theory, there is also a notion of Bottom there.....and shouldn't Bottom be defined based on what's the order defined?
回答1:
Indeed there is an order of definedness, where bottom is the least defined value. Have a look at this page about denotational semantics in Haskell for a more thorough explanation.
Here is a lattice for the values of Maybe Bool taken from the wiki page. It shows that Just True is more defined than Just ⊥ which is more defined than ⊥.
来源：https://stackoverflow.com/questions/6379458/the-concept-of-bottom-in-haskell