Make Eq type class single method

[Tom Ellis]

On Wed, Oct 20, 2021 at 04:39:21PM +0200, Joachim Breitner wrote:
> I am revisiting some educational material about Haskell, and I stumble
> over something that I keep stumbling over. I thought there was prior
> discussion, but I couldn’t find it (operators hard hard to google for).
> 
> Why does Eq have a (/=) method?

Perhaps sometimes it is easier to define (/=) and use the default
definition of (==) in terms of it?