Post History

Make my number a set

## Natural to set

(set meaning an unordered collection with no duplicates, though answers may use and output lists instead)


Recently I was brainstorming what a language with only (arbitrarily nested) sets would be like. A number is represented with a set of that many elements. The elements need to be different, which leads to this definition:

# Definition

- The set representation of \$0\$ is the empty set.
- The set representation of any other integer \$n\$ is the set of the set representations of all positive integers less than \$n\$, including zero.
- Negative, complex, or rational numbers do not need to be handled.
- Your full program or function is to convert from a positive integer to a set or list.

## Examples

```
0 {}
1 {{}}
2 {{}, {{}}}
3 {{}, {{}}, {{}, {{}}}}
```