“…This is similar to the calculation of IIB-supergravity and M-theory in [31]. We use the following conventions for the indices: A, B, C ∈ {+, −,1, ..,4, 1, .., 4}, α, β ∈ {1, .., 4} and k, l, m, n ∈ {1, .., 4} with the restriction k, l, m, n = α, β.…”