The last time that this topic was brought up, competing demands voiced by different people were not possible to reconcile: 1) Equatable `==` must be a full equivalence relation. 2) Floating-point types must conform to `Equatable` and not to some alternative such as `PartiallyEquatable`. 3) Floating-point `==` must be IEEE-compliant (at least in the concrete context), and therefore *not* a full equivalence relation. 4) IEEE-compliant floating-point equivalence must be spelled `==` and not some alternative such as `&==`. 5) Behavior of `==` must not change between generic and concrete contexts.