9 Further, subsection (5) expressly provides that 'the question' can only be referred to the Tribunal if the leave of the Tribunal has been obtained, where the basis for the reference to the Tribunal is the failure of a person to act to resolve the question 'under subsection (3)(a) or (b)'. The terminology used in this subsection lacks precision because, strictly speaking, the power of a person to 'act' does not arise under the subsection but under the term which the subsection implies into the lease agreement. However, it is clear enough that the expression refers to the circumstance in which a valuer appointed by a party or the parties to the lease, has not acted so as to give effect to the term implied into the lease agreement. The requirement for the grant of leave in such a circumstance provides an opportunity for the Tribunal to inquire into the reasons why the term implied by the statute has failed to achieve its purpose. Thus, for example, in deciding whether to grant leave, the Tribunal may consider whether all reasonable steps have been taken to enable a valuer to be appointed by agreement between the parties and for that valuer to resolve the question of the rent payable following review, or for the parties to each appoint a valuer in default of agreement as to a single valuer. Viewed in this way, the requirement for the grant of leave is consistent with the evident scheme of the statute, which is to provide a mechanism by which the parties might, through the appointment of a valuer or valuers, resolve the question, but providing an avenue of resort to the Tribunal if, and only if, the mechanisms provided by the implied term have failed to achieve their objective.