If individual provisions of these Standard Terms and Conditions of Purchase and Delivery are void or invalid, this shall in no way affect the remaining provisions thereof. If and insofar as the contract or these Standard Terms and Conditions of Purchase and Delivery should have any lacunae, such gaps shall be filled by such legally effective provisions which best satisfy the underlying economic purpose of this contract and the purpose of these Standard Terms and Conditions of Purchase and Delivery intended by the contracting parties, if they had been aware of such gap.