a [1] b1 [2] b2 [2] b3 [2]
a-a [a] a-b1 [b] a-b2 [b]
A-a [A] A-b1 [B] A-b2 [B]
r-a [i] r-b1 [ii] r-b2 [ii]
R-a [I] R-b1 [II] R-b2 [II]
d-a [1] d-b1 [2] d-b2 [2]
g-a [α] g-b1 [β] g-b2 [β]
X-a [abcdefgh 1] X-b1 [abcdefgh 2] X-b2 [abcdefgh 2]