References
  
  [ABM07]  Araujo,  J.,  Bunau,  P.  v.  and  Mitchell,  J.  D., Computing
  automorphisms of semigroups,  (2007), (submitted for publication)
  
  [AR00] Arthur, R. E. and Ruskuc, N., Presentations for two extensions of
  the  monoid  of  order-preserving  mappings on a finite chain, Southeast
  Asian Bull. Math., 24, 1 (2000), 1--7
  
  [GH92]  Gomes,  G.  M.  S.  and  Howie,  J.  M., On the ranks of certain
  semigroups  of  order-preserving transformations, Semigroup Forum, 45, 3
  (1992), 272--282
  
  [GM05]  Gray,  R. and Mitchell, J. D., Largest subsemigroups of the full
  transformation monoid, Discrete Math. (2005), (to appear)
  
  [How95]  Howie,  J.  M., Fundamentals of semigroup theory, The Clarendon
  Press  Oxford  University Press, London Mathematical Society Monographs.
  New Series, 12, New York (1995), x+351, (Oxford Science Publications)
  
  [KM05]  Kudryavtseva,  G.  and  Mazorchuk, V., On Kiselman's semigroup, 
  (2005), (arXiv:math/0511374v1)
  
  [LM90]  Lallement,  G. and McFadden, R., On the determination of Green's
  relations  in finite transformation semigroups, J. Symbolic Comput., 10,
  5 (1990), 481--498
  
  [LPRR98]  Linton,  S. A., Pfeiffer, G., Robertson, E. F. and Ruskuc, N.,
  Groups  and  actions  in  transformation  semigroups,    Math. Z.,  228 
  (1998), 435--450
  
  [LPRR02]  Linton,  S. A., Pfeiffer, G., Robertson, E. F. and Ruskuc, N.,
  Computing transformation semigroups,  J. Symbolic Comput. ,  33  (2002),
  145--162
  
  
  
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