B but does not belong to both Is the same as: x belongs to the union of A with B less the intersection of A with B. Math notation: In computing: XOR 16 x ∈ (A ∆ B) ⟺ (x ∈ A) ⊻ (x ∈ B)

any numeric types that implement the needed operators): Compound interest in Java, if you need to use a non-primitive numeric type such as BigDecimal: 37

objects should implement __repr__, __eq__. Pythonic collections should implement __len__, __iter__, __contains__, and accept iterable arguments. Check out this example showing how to implement class designed for dense sets of small integers: Much more about these subjects in Fluent Python. 42 https://github.com/standupdev/uintset