Implicit Types (s t u v : {perm T}) (x y z a b : T).(* Note that pcycle s x is the orbit of x by <[s]> under the action aperm. *)
(* Hence, the pcycle lemmas below are special cases of more general lemmas *)
(* on orbits that will be stated in action.v.                              *)
(*   Defining pcycle directly here avoids a dependency of matrix.v on      *)
(* action.v and hence morphism.v.                                          *)

Definition aperm x s := s x.

Lemma odd_permJ s1 s2 : odd_perm (s1 ^ s2) = odd_perm s1.