  Recently it has been found [G. Pruessner and H. J. Jensen, Phys. Rev. Lett.
91, 244303 (2003)] that a totally asymmetric variant of the Oslo model [K.
Christensen et al., Phys. Rev. Lett. 77, 107 (1996)] represents the entire
universality class of the Oslo model with anisotropy. The totally asymmetric
model can be solved without scaling assumptions by finding recursively the
eigenvectors of the Markov matrix, which can be suitably modified to produce
the moment generating function of the relevant observable. This method should
be applicable to many other stochastic processes.
