This package is not currently in any snapshots. If you're interested in using it, we recommend adding it to Stackage Nightly. Doing so will make builds more reliable, and allow stackage.org to host generated Haddocks.
The laws of Eq only require that you have a decidable equivalence relation defined on a type; they do not force you to guarantee abstraction with respect to the relation, i.e. you can write anti-extensional operations without violating the laws. This package provides an alternative for when functionality with respect to an equivalence relation is desired.