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Version: 5.x

AND, OR, NOT, XOR operators

AND, OR, NOT, XOR operators that create properties that implement logical operations.


expression1 AND expression2
expression1 OR expression2
expression1 XOR expression2
NOT expression1


  • expression1, expression2

    Expressions whose values will be the operator arguments. Expression values are considered to be BOOLEAN class values depending on whether they are NULL or not.


likes = DATA BOOLEAN (Person, Person);
likes(Person a, Person b, Person c) = likes(a, b) AND likes(a, c);
outOfInterval1(value, left, right) = value < left OR value > right;
outOfInterval2(value, left, right) = NOT (value >= left AND value <= right);