Table 1.

Common non-concept predicates used in the EHR question corpus.

Predicate	Description
δ(S)	Whether the set S is non-empty
at_location(a, τ)	Whether event a occurred at the location denoted by the string τ
greater_than(a, b), less_than(a, b)	Whether the value of event a is greater or less than the value of b
is_result(a, n)	Whether n is the result of event a
latest(S)	Returns the most recent event in set S
max(S), min(S)	Largest/smallest value in set S
positive(S), negative(S)	Filters the events in set S, returning only the positive/negative events (diagnostic tests, disease diagnoses, etc.)
sum(S)	Sum of the results in set S
time(a)	The time of event a
time_within(a, τ)	Whether event a is within the time denoted by the string τ