"16. Sub-section (4) operates in two ways. By what I might call its first branch, it operates, in effect, by way of varying of the provisions of the lease: the lease is to be taken to provide that the last day for the exercise of the option is the day that is three months after the landlord gives the notice required by sub-section (3). The second branch of sub-section (4) does its work, not by way of varying the provisions of the lease, but by way of providing what the operation or effect of the lease is to be: if the date which the lease is to be taken to fix as the last day for exercising the option is later than the date of the expiry of the term of the lease, the lease is to continue until that date unless the tenant determines it pursuant to sub-s. (9). As regards the first branch of sub-s. (4), I find it extremely difficult to see how it could be said that, by implication from the suggested purpose of the section, some subsequent event is to affect the reforming of the lease which has already occurred by force of sub-s. (4): the lease is to be taken to make a certain provision, and I should have thought that it must be taken to continue to make that provision notwithstanding later events. (Emphasis added) 17. It is unnecessary for us to decide what effect the purported exercise of the option on 29 January 1998 would have had if it had been in all respects effectual, although I may say that I have little doubt that, one way or another, it would have been possible to arrive at a satisfactory resolution of the question how sub-s. (4) was to be squared with the effective exercise of the option, on the basis that Parliament must have intended that the statutory extension of the term should not stand in the way of the creation of the new term upon which the parties had agreed. But, as I say, that is not this case on the facts. All that the landlords have in this case as a supervening event is the purported exercise of option on 29 January 1998, good as to manner and form but bad as to substance. I am not persuaded that, as a matter of implication from the purpose of the legislation, on the proper construction of s. 14 that event had the result that sub-s. (4) did not cause the lease to continue beyond the date of the expiry of the term. What I have called the first branch of sub-s. (4) in effect altered the lease by enlarging the time for the exercise of the option of renewal. Why should one conclude that Parliament intended that a defective exercise of option, whether bad in form or bad in substance or bad in both respects, should cause the second branch of sub-s. (4) to cease to operate? If the defect was merely one of manner or form, then a tenant could rectify the situation by giving a further notice without the defect. If the defect was one of substance, the tenant might cure that defect and then give a further notice. I do not think it can be said that Parliament intended that the consequence contended for by the present landlords was to ensue."