if (idx1 == idx2)
g[j] -= Y[i] * X[mi(i,idx3,n,d)];
if (idx1 == idx3)
g[j] -= Y[i] * X[mi(i,idx2,n,d)];
if (idx2 == idx3)
g[j] -= Y[i] * X[mi(i,idx1,n,d)];
if (idx1 == idx2)
g[j] -= Y[i] * X[mi(i,idx3,n,d)];
if (idx1 == idx3)
g[j] -= Y[i] * X[mi(i,idx2,n,d)];
if (idx2 == idx3)
g[j] -= Y[i] * X[mi(i,idx1,n,d)];