Figure 4.10.2.  (a) The four interscalar transpositions from the C half-diminished seventh chord to the C dominant seventh chord.  (b) The minimal voice leading between the C half-diminished and F dominant seventh chords combines the third of these interscalar transpositions with chromatic transposition upward by five semitones.  (c) The minimal (four-voice) voice leading between any half-diminished and dominant seventh chords combines one of these interscalar transpositions with a chromatic transposition.  Again, as the chromatic transposition increases, the descending interscalar transposition increases as well, so that the two forms of transposition cancel out.