Change the types of cm_x, Uncommitted^Orchard, and ak in Orchard to { 0 .. q_P-1 }, avoiding type errors and reflecting the implementation in zcashd. This eliminates all uses of P_x (except that ak in an Orchard full viewing key is still required to be a valid Pallas affine x-coordinate). Also clarify the coordinate system whenever we refer to coordinates.
Change the types of cm_x, Uncommitted^Orchard, and ak in Orchard to { 0 .. q_P-1 },
avoiding type errors and reflecting the implementation in zcashd. This eliminates all uses of P_x
(except that ak in an Orchard full viewing key is still required to be a valid Pallas affine
x-coordinate). Also clarify the coordinate system whenever we refer to coordinates.

Signed-off-by: Daira Hopwood <cd7d43d5556a38ce626d53826fddc46adc597539@jacaranda.org>

zcash/zips,zcash/zips,zcash/zips,zcash/zips