On Mon, Mar 10, 2008 at 3:12 PM, Neil Mitchell <[EMAIL PROTECTED]> wrote: > Hi > > > > "The Ord class is used for totally ordered datatypes." > > > > This *requires* that it be absolutely impossible in valid code to > > distinguish equivalent (in the EQ sense, not the == sense) things via > > the functions of Ord. The intended interpretation of these functions is > > clear and can be taken as normative: > > > > forall f . (compare x y == EQ and (f x or f y is defined)) > > ==> f x == f y) > > Are you sure? I would have read this as the ordering must be > reflexive, antisymetric and transitive - the standard restrictions on > any ordering. See http://en.wikipedia.org/wiki/Total_ordering
This is my reading, too. In addition, to make it total, the property that any two elements are comparable (this is the property that a partial order does not necessarily have). -- Denis _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
