diffops dot: fdotg not a vector when g is a tensor

[gome0803]

Dear channelflow developers,
I have a question concerning the function dot() in diffops.cpp
I have troubles understanding the computation of fdotg when f.Nd= 3 and g.Nd = 9.

fdotg(nx, ny, nz, 0) += f(nx, ny, nz, i) * g(nx, ny, nz, ij)

shouldn’t it be
fdotg(nx, ny, nz, i) += f(nx, ny, nz, j) * g(nx, ny, nz, ij)
just like in dotgrad ?