fact: Fixpoint rTreeGetP (t : rTreeP) (r : rNat) {struct r} : POption := match r, t with | _, rEmptyP => PNone | BinPos.xH, rSplitP a _ _ => a | BinPos.xO p, rSplitP _ t' _ => rTreeGetP t' p | BinPos.xI p, rSplitP _ _ t' => rTreeGetP t' p end.
imports: Coq(ZArith) Stalmarck(normalize) Coq(Classical) Stalmarck(sTactic)