Bool_t Propagate(Double_t xr) { return Propagate(GetAlpha(),xr); }
Bool_t MeanBudgetToPrimVertex(Double_t xyz[3], Double_t step, Double_t &d) const;
Bool_t Improve(Double_t x0,Double_t xyz[3],Double_t ers[3]);
Bool_t Propagate(Double_t xr) { return Propagate(GetAlpha(),xr); }
Bool_t MeanBudgetToPrimVertex(Double_t xyz[3], Double_t step, Double_t &d) const;
Bool_t Improve(Double_t x0,Double_t xyz[3],Double_t ers[3]);