2.1.2  Sufficient proof of an anti -doping rule violation under Article 2.1  is established by any of the following: presence of a Prohibited  Substance or its Metabolites or Markers in the Athlete’s A Sample  where the Athlete waives analysis of the B Sample and the B Sample is not analysed; or, where the Athlete’s B Sample is analy sed and the  analysis of the Athlete’s B Sample confirms the presence of the  Prohibited Substance or its Metabolites or Markers found in the  Athlete’s A Sample ; or where the Athlete’s A or B Sample is split into two  parts and the analysis of the confirmation part of the split Sample  confirms the presence of  the Prohibited Substance or its Metabolites or Markers found in the first  part of the split Sample or the Athlete waives analysis of the confirmation part of the split S ample .