A commercial exporter in the United States attempts to contract with a Mexican buyer for the sale of a container load of house wares. The exporter's pro forma invoice is dated and sent August 20^th. The Mexican acceptance is mailed on August 30^th and received by the exporter on September 9^th. The exporter, however, mailed a revocation of its offer on September 3^rd, which was received by the Mexican party on September 10^th. Is this transaction subject to the CISG? Is there a contract? Why or why not, and when was it either formed or terminated?