^{4}The justiﬁcation of the terms (y_{1} −1) and (y_{i}+1) is as follows. Recall that (y_{1},…,y_{C}) ∈ 𝕐 = {1,2}×{−1,0,1}^{C−1}.
Thus, y_{1} ∈{1,…,3^{Q+2}} implies that (y_{1} − 1) ∈{0,1,…,3^{Q+2} − 1}, while y_{i} ∈{−1,0,1} implies that
(y_{i} + 1) ∈{0,1,2}.