Minor + (Major - Mixolydian) = Harmonic Minor

[0 2 3 5 7 8 10 12] + ([0 2 4 5 7 9 11 12] - [0 2 4 5 7 9 10 12]) =

[0 2 3 5 7 8 10 12] + [0 0 0 0 0 0 1 0] = [0 2 3 5 7 8 11 12]

Because Linear Algebra is legit