help uniquestrata
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Title

    uniquestrata -- Check that the specified variables collectively account
        for every observation


Syntax

        uniquestrata varlist


Description

    uniquestrata takes a varlist of strata variables and calculates whether
    all combinations of the levels of those strata variables add up to the
    total number of observations--no more, no less.  If not, the program
    returns error 9.

    Mathematically, it simply multiplies together the number of distinct
    levels of each strata variable given in varlist and compares that to the