[Haskell-cafe] Re: Wikipedia on first-class object

Wolfgang Jeltsch wrote:

If x doesn’t equal y, x == y is False, but if x equals y, x == y might be True or undefined.

x == y may be _|_ for the False case, too, depending on its implementation (like first comparing all list elements on even indices and then comparing all list elements on odd indices). But the standard == for lists has indeed the stated property. Regards, apfelmus