P.J. Cameron had mentioned that "It can be shown that a permutation group is transitive if and only if its centralizer in the symmetric group is semiregular, and vice versa （Wielandt, page 9）."[1] The latter is true, i.e. G≤SΩ is semiregular（?）CsΩ（G） is transitive. [cf. 2] But in the former statement fails, i.e. CsΩ（G） is semiregular（?）G≤SΩ is transitive. In ...
