[Tutor] Confusion about definition of proper subset in python set

[dn]

On 30/10/2020 15:52, Manprit Singh wrote:
> Dear sir ,
> 
> Consider explanation given about  set < other in python official
> documentation
> 
> Test whether the set is a proper subset of *other*, that is, set <= other
> and set != other.
> 
> This confuses me actually.
> 
> set <= other   and set != other , how it is possible at same time ?
> 
> As far as i know, if S is a set and ss is its proper subset, then ss is
> strictly contained in S and necessarily excludes at least one member of S.
> 
> Need some light on it.


Create some sample set-data including identical sets, exclusive sets, 
and super- plus sub-sets.

Run tests in the REPL, and show us how you have proven the above, or 
otherwise...
-- 
Regards =dn