Changes

0.1.2

The definition of sign has been updated for spelled pitches:
- Unisons now have a direction (e.g., sign(a1:0) == 1).
- As a consequence, the alteration of d1:0 (= -a1:0) is now 1 because it is considered downward.
- The interval class d1 is considered downward:
- For interval classes, sign takes the shortest realization (as before) but alteration always considers the upward interval (as in printing).-