Function Reference: B
@before Indicators for whether observation precedes a date.
@beta Beta integral (Euler integral of the second kind).
@betaincder Derivative of the incomplete beta integral.
@betalog Natural logarithm of the beta integral.
@between Dummy variable for value within range of values.
@binomlog Natural logarithm of the binomial coefficient.
@bridge Copy of a series using the current or preceding non-missing value.