Summary table with transform column of row() is one more option (and there are plenty more)
Names Default To Here(1);
dt = Open("$SAMPLE_DATA/Big Class.jmp");
dt_summary = dt << Summary(
Group(:weight),
Min(Transform Column("Row", Formula(Row()))),
Freq("None"),
Weight("None"),
statistics column name format("column"),
private
);
dt_summary << Sort(By(:Row), Replace Table, Order(Ascending));
unique = dt_summary[0, 1];
Close(dt_summary, no save);
show(unique);
-Jarmo