This is from the book "tonal harmony",
the 14th chord is vii half diminished 7; consisting of the notes D# F# A C#, with A in the bass, therefore it is vii half diminished 4 3, second inversion, which makes sense to me
but the 16th chord is what's confusing me, it has notes F# A D#, without a C#, the textbook answer says it's vii half diminished 6, first inversion, but can a triad be half diminished? I thought only seventh chords could be HALF diminished, the 6 clearly states that it's a TRIAD in first inversion, and the slashed circle states that it is half diminished,
so can a TRIAD be half diminished?
(UPDATE) It seems there are multiple errors/typos in this book, I have spotted even more typos after further reading