MathType of mixed Scalars and Fields

Hi,

In general, what should the VisAD MathType be of a dataset that
comprises two Scalars and one Field?  Should it be the Tuple

    (scalar1, scalar2, field)

or the Tuple

    ((scalar1, scalar2), field)

I.e. should the scalar components be "broken out" of their own Tuple or
not?

--Steve