definiens: as such term is defined in the Rights Agre ement, because either ( a ) the Shares, by themselves, constitute in excess of twen ty percent ( 20 % ) of then- outstanding Common Stock of [COMPANY] ( the ), or ( b ) after the date hereof but prior to the Closing Date Aventis acquir es a third party that owns capital stock of [COMPANY] and whose ownership of capital stock of [COMPANY] is not the primary business purpose of such third p arty ( the ), and when the Shares are added t ogether with Third Party [COMPANY] Stock, Aventis 's aggregate beneficial ow nership exceeds the Threshold, then prior to the _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Page 17 consummation of the Closing, [COMPANY] shall cause the Rights Agreement to be amended to ensure that the acquisition of the Share s at such Closing does not cause Aventis to become an Acquiring Person . Notwit hstanding the foregoing, nothing in this Section 8.3 shall require ViroPharm a to amend the Rights Agreement if Aventis 's purchase of the Shares would result in Aventis becoming an Acquiring Person because such Shares, when added to any shares of the capital stock of [COMPANY] acquired by Aventis other than under this Agreement or as specifically described in clause ( b ) of this Sectio n 8.3, causes Aventis 's ownership to exceed the Threshold