MENSA-BOION J.
By a deed dated 14 December 1960, the plaintiff, referred to as the sub-lessor, leased certain premises to the defendants for a term of fifteen years commencing from 1 December 1960; so however that the defendants had the option to determine the lease at the expiration of the first ten years. That was provided by clause 4 (b) as follows:
“(b) If the company [i.e. the defendants] desire to determine the present demise at the expiration of the first ten (10) years of the said term and shall give to the sub-lessor not less than six (6) calendar months written notice of such desire and shall up to the time of such determination pay the rent and perform and observe the covenants on its part hereinbefore contained shall immediately on the expiration of such notice the present demise and everything herein contained shall cease and be void but without prejudice to the remedies of either party against the other ...”
By a letter dated 14 May 1970, and exhibited as exhibit B, the def…