Permutations on the Random Permutation

  title={Permutations on the Random Permutation},
  author={Julie Linman and Michael Pinsker},
  journal={Electron. J. Comb.},
The random permutation is the Fraisse limit of the class of finite structures with two linear orders. Answering a problem stated by Peter Cameron in 2002, we use a recent Ramsey-theoretic technique to show that there exist precisely 39 closed supergroups of the automorphism group of the random permutation, and thereby expose all symmetries of this structure. Equivalently, we classify all structures which have a first-order definition in the random permutation. 

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