Commit d032a372 authored by simonpj's avatar simonpj
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[project @ 2005-02-09 14:02:31 by simonpj]

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parent bc28236a
......@@ -1844,11 +1844,11 @@ We have to be careful here. If we are *given* d1:Ord a,
and want to deduce (d2:C [a]) where
class Ord a => C a where
instance Ord a => C [a] where ...
instance Ord [a] => C [a] where ...
Then we'll use the instance decl to deduce C [a] and then add the
Then we'll use the instance decl to deduce C [a] from Ord [a], and then add the
superclasses of C [a] to avails. But we must not overwrite the binding
for d1:Ord a (which is given) with a superclass selection or we'll just
for Ord [a] (which is obtained from Ord a) with a superclass selection or we'll just
build a loop!
Here's another variant, immortalised in tcrun020
......
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