Assertion: predicate's value | /r/HasProperty | null
Facets:
Source sentences:
text: If either value is NULL, then the result of the predicate is UNKNOWN.
text: If there are no two rows in <table subquery> such that the value of each column in one row is non- NULL and is not distinct from the value of the corresponding column in the other row, then the result of the <unique predicate> is TRUE ; otherwise, the result of the <unique predicate> is FALSE .
text: If the value of any of the arguments is NULL, then the result is UNKNOWN.