How to union nested Sets / A single set from nested sets?

[Oscar Benjamin]

On 4 January 2016 at 02:40, mviljamaa <mviljamaa at kapsi.fi> wrote:
> I'm forming sets by set.adding to sets and this leads to sets such as:
>
> Set([ImmutableSet(['a', ImmutableSet(['a'])]), ImmutableSet(['b', 'c'])])
>
> Is there way union these to a single set, i.e. get
>
> Set(['a', 'b', 'c'])

Where are you getting Set and ImmutableSet from? Is that sympy or something?

--
Oscar