>>> print({2*x for x in range(1,5)})
set([8, 2, 4, 6])
# je tam 2, 4, 6, 8 .. nic nechybí => OK
https://docs.python.org/3/library/stdtypes.html#set
A set object is an unordered collection of distinct hashable objects.
Co je nejasneho na slove neusporadana?