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(* as published by the Free Software Foundation; either version 2.1   *)
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(* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the      *)
(* GNU General Public License for more details.                       *)
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(* 02110-1301 USA                                                     *)
Definition BDDvar_le := Nleb.
Definition BDDvar_max (x y : BDDvar) := if BDDvar_le x y then y else x.

Lemma lt_max_nat_of_N :
forall x y z : BDDvar,
BDDcompare (BDDvar_max x y) z = Datatypes.Lt ->
max (nat_of_N x) (nat_of_N y) < nat_of_N z.