Set operators
Operator Operation Operand types Result type Example
+ union set set Set1 + Set2
- difference set set S - T
* intersection set set S * T
<= subset set Boolean Q <= MySet
>= superset set Boolean S1 >= S2
= equality set Boolean S2 = MySet
<> inequality set Boolean MySet <> S1
in membership ordinal, set Boolean A in Set1
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