“In my judgment by charging value added tax on the rent the Appellant made an election… There is nothing in the paragraph or, so far as I can see, elsewhere which lays down the manner in which an election is to be made. Since the Appellant had no right to charge value added tax on the rent except by making an election…, in my judgment by demanding and receiving value added tax on the rent the Appellant was clearly indicating its decision that thenceforth its supplies in relation to the property were no longer to be exempt from tax…”