[Haskell-cafe] What puts False before True?

jerzy.karczmarczuk at info.unicaen.fr jerzy.karczmarczuk at info.unicaen.fr
Thu May 31 05:31:49 EDT 2007


This question: 

>> > What is the basic philosophy for Bool being a member of Ord?
...
>> > What justifies False < True?

resulted in some answers: 

>> in most interpretations this equals: 
>> 
>> False == 0
>> True == 1
... 

Although this is not a must, I would like to remind you also that
in formal math there *IS* a strong relation between the ordering
and binary 'algebraic' relation. The Boolean algebra / Boolean lattice
in a nice structure, and Ord could in principle be derived from
the login connectives. But this is a subsumption, which in Haskell
cannot be done automatically, so we do it explicitly...
See here: 

http://en.wikipedia.org/wiki/Boolean_algebra 

Jerzy Karczmarczuk 



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