
19 Jul
2009
19 Jul
'09
9:51 a.m.
On 18 Jul 2009, at 16:49, Wolfgang Jeltsch wrote:
Am Samstag, 18. Juli 2009 08:58 schrieb Miguel Mitrofanov:
Oops... Sorry, wrong line. Should be
isAB :: forall p. p A -> p B -> p x
Is this a well-known approach for closing classes?
I have an impression that this is kinda folklore. But I can't provide any references; I don't even remember if I invented it myself or not.