Equation Icon  R ˆ(1,0) ˆ(1,1) i 2 htt = A + sA( i ω + O (s ), ) (23.20 ) hR = Cˆ(1,0)+ s ˆB (1,1)ωa + Cˆ(1,1)ωi + 𝜖aijD ˆ(1,1)ωi + O (s2), (23.21 ) ta a ( ai j ) hR = δ Kˆ(1,0) + Hˆ(1,0)+ s δ ˆK (1,1)ωi + ˆH (1,1)ωi + 𝜖 j ˆI(1,1)ωi + ˆF(1,1)ω + O (s2). (23.22 ) ab ab ab ab i abi i (a b)j ⟨a b⟩