= Set
{disambiguate=mathematics}
= Set
{synonym}
Intuitively: unordered container where all the values are unique, just like C++ `std::set`.
More precisely for set theory <formalization of mathematics>:
* everything is a set, including the elements of sets
* string manipulation wise:
* `{}` is an empty set. The natural number `0` is defined as `{}` as well.
* `{{}}` is a set that contains an empty set
* `{{}, {{}}}` is a set that contains two sets: `{}` and `{{}}`
* `{{}, {}}` is not well formed, because it contains `{}` twice