REPLACE SECOND SENTENCE WITH THE FOLLOWING: Until the first death, either may withdraw from the arrangement by giving notice to the other party, and no trust interest arises for the intended beneficiary of the agreement: Stone v Hoskins [1905] P. 194; Barns v Barns [2003] HCA 9, (2003) 214 C.L.R. 169 at [85].  Cf. T.G. Youdan (1979) 24 U.Tor.L.J. 390 at 406-410.

REPLACE THIRD SENTENCE WITH THE FOLLOWING: Any material alteration by one party of his will will prevent the arrangement from being binding on the survivor.  The court is not in a position to assess the significance of the alteration to the parties, or whether it was subjectively intended to revoke the arrangement: Re Hobley (1997) [2006] W.T.L.R. 467.