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(* Micromega: A reflexive tactic using the Positivstellensatz           *)
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(*  Frédéric Besson (Irisa/Inria) 2006-2008                             *)
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Open Scope R_scope.

Lemma yplus_minus : forall x y,
0 = x + y -> 0 =  x -y -> 0 = x /\ 0 = y.