[Haskell-cafe] IO is not a monad (and seq, and in general _|_)

[Brandon S. Allbery KF8NH]

Can someone explain to me, given that (a) I'm not particularly expert  
at maths, (b) I'm not particularly expert at Haskell, and (c) I'm a  
bit fuzzybrained of late:

Given that _|_ represents in some sense any computation not  
representable in and/or not consistent with Haskell, why/how is  
reasoning about Haskell program behavior in the presence of _|_ *not*  
like reasoning about logic behavior in the presence of (p^~p)->q?

-- 
brandon s. allbery    [linux,solaris,freebsd,perl]     allbery at kf8nh.com
system administrator [openafs,heimdal,too many hats] allbery at ece.cmu.edu
electrical and computer engineering, carnegie mellon university    KF8NH