149. Rectification on the grounds of common mistake.

Subject to the exceptions regarding unilateral mistake1, rectification2 of a lease will not be granted unless there is a mistake that is common to all the parties3. There must be:

  1.  

    (1)     a continuing common intention, whether or not amounting to an agreement, in respect of a particular matter in the lease to be rectified;

  2.  

    (2)     an outward expression of accord (which may be written evidence or an oral agreement)4;

  3.  

    (3)     an intention such as is described in head (1) above at the time of the execution of the lease sought to be rectified; and

  4.  

    (4)     a mutual mistake5, which