I.5.4 Dyadic operators

Eight such operators have been defined. One first explains the meaning and behavior of the four elementary dyadic operations.

• “+” operator returns the union of two ResKeyLists.
• “-” operator returns the difference of two ResKeyLists.
• “*” operator returns the intersection of two ResKeyLists.
• “/” operator: if $x$ and $y$ are two ResKeyLists, then $x∕y=\left(x+y\right)-\left(x*y\right)$. (The operation is equivalent to a logical “exclusive or” operation on the entities.)