VARIATIONS OF TERMS. It is hereby expressly agreed and declared by the Parties hereto that notwithstanding any of the provisions of this Agreement to the contrary, the provisions and terms of this Agreement may at time to time be varied or amended by means of an exchange of letters or such other means as the parties may agree from time to time in writing and executed by the Parties and thereupon such amendments and variations shall be deemed to have been amended or varied accordingly and shall be read and construed as if such amendments and variationshave been incorporated into and had formed part of this Agreement at the time of execution hereof.