End REC_INC_XY.
Section REC_INC_ALT.
(* structure de file d'attente *)
Variable c0 : Config.
Variable s0 s1 s2 : Site.
Hypothesis s2_not_owner : s2 <> owner.

Lemma rinc_trans_alt :
alternate (bm c0 s0 owner) ->
alternate (bm (rec_inc_trans c0 s1 s2) s0 owner).