Error on the rotation averages using a synthetic rotation profile. Starting with the seismic model of KIC 012008916, we selected all the modes that had a trapping parameter ζ smaller than a particular cut-off. The total number of modes in the model is 45 (cutoff ζ = 1). We computed two-zone inversions using synthetic splittings from modes with trapping parameters smaller than a given ζ cutoff. More splittings used certainly improve the error on the predicted rotation averages, but this does not take into account any systematic errors that may be present.