>>12064736>What's the differenceThe first is silly.
The only element of the first set is Z.
This would imply that 2 = Z.
2 = {..., -2, -1, 0, 1, 2, ...} = {..., -2, -1, 0, 1, {..., -2, -1, 0, 1, {..., -2, -1, 0, 1, {..., -2, -1, 0, 1, {...}}, ...}}, ...}}, ...}
This isn't necessarily "wrong", but it is really gay, hence why axiomatic set theories don't allow sets to contain themselves.
