Moritz Lenz wrote:
>> 2. set is unordered collection of values， subset is new type. People are
>> apt to confuse the two concepts.
>
> Note that people never write "subset" in their code, the write things like
> sub f($x where { ... } ) and the "where" constructs the subset type. I
> don' think that's... all that confusing. Forgot to finish the sentence... :/
