Equality in particular is a tricky subject with languages that have reference types and subtypes. Even C# and Java define equality between all types ("5".Equal

Equality in particular is a tricky subject with languages that have reference types and subtypes. Even C# and Java define equality between all types ("5".Equals(5) is false, not an error). Still, I wasn't trying to defend dynamic typing over static typing, just pointing out how to conceptualize the dynamic language decision in terms of type theory, to point out that it's not surprising.