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(* 02110-1301 USA                                                     *)
(** lemmas. Some nice lemmas, mostly about le, lt, and mult.  @author Olga Caprotti and Martijn Oostdijk @version $Revision$ *)
Global Set Asymmetric Patterns.

Lemma le_le_mult : forall b a c d : nat, a <= b -> c <= d -> a * c <= b * d.