31 May
2007
31 May
'07
2:14 p.m.
Roberto Zunino wrote:
Ah, silly me! I checked that inequality was preserved, but forgot that (==) diverges on infinite list!
Indeed, strictly speaking, Eq [] does not satisfy the Eq invariant x==x.
All haskell types contain divergence. So all Eq types have exactly this same problem. We 'like' infinite lists because they are a kind of 'productive divergence'. But they still diverge. Jules