@before Indicators for whether observation precedes a date.

@beta Beta integral (Euler integral of the second kind).

@betainc Incomplete beta integral.

@betaincder Derivative of the incomplete beta integral.

@betaincinv Inverse of the incomplete beta integral.

@betalog Natural logarithm of the beta integral.

@between Dummy variable for value within range of values.

@binom Binomial coefficient.

@binomlog Natural logarithm of the binomial coefficient.

@bounds Bounded values.

@bridge Copy of a series using the current or preceding non-missing value.