4.—(1) Subject to sub-paragraph (2), any sum directly attributable to the proceeds of sale of any dwelling formerly occupied by the relevant person as his only or main residence to the extent to which it is to be used for the purchase of either—
(a)the dwelling or building to which the application relates, or
(b)any dwelling, other than that to which the application relates, which is intended for such occupation within 26 weeks of the date of sale or such longer period as is reasonable in the circumstances to enable the relevant person to complete the purchase.
(2) Sub-paragraph (1) shall not apply where a dwelling is disregarded under paragraph 26, and sub-paragraph (1)(b) shall not apply where a dwelling is disregarded under paragraph 3.