Sat, 10 Feb 2001 11:25:46 -0500, Dylan Thurston
Can you elaborate? What do you mean by signum for functions? The pointwise signum?
Yes.
Then abs would be the pointwise abs as well, right?
Yes.
That might work, but I'm nervous because I don't know the semantics for signum/abs in such generality.
For example signum x * abs x == x, where (==) is not Haskell's equality but equivalence. Similarly to (x + y) + z == x + (y + z). If (+) can be implicitly lifted to functions, then why not signum? Note that I would lift neither signum nor (+). I don't feel the need. It can't be uniformly applied to e.g. (<) whose result is Bool and not some lifted Bool, so better be consistent and lift explicitly. -- __("< Marcin Kowalczyk * qrczak@knm.org.pl http://qrczak.ids.net.pl/ \__/ ^^ SYGNATURA ZASTÊPCZA QRCZAK