text: Deferred tax assets and liabilities arise from temporary differences 
  between the carrying amounts of the assets and liabilities we record in 
  our consolidated statements of financial position and their respective 
  tax bases. We calculate deferred tax assets and liabilities using enacted 
  or substantively enacted tax rates that will apply in the years the 
  temporary differences are expected to reverse. 
  
  there is a legally 
  Deferred tax assets and liabilities are offset 
  enforceable right to offset current tax liabilities and assets and they 
  relate to income taxes levied by the same authority on: 
  (cid:129) the same taxable entity, or 
  (cid:129) different tax entities where these entities intend to settle current tax 
  liabilities and assets on a net basis or the tax assets and liabilities will 
  be realized simultaneously. 
  
  if 
  
  We recognize a deferred tax asset for unused losses, tax credits and 
  deductible temporary differences to the extent that it is probable that 
  future taxable income will be available to use the asset. We use 
  judgement to evaluate whether we can recover a deferred tax asset 
  based on our assessment on existing tax laws, estimates of future 
  profitability and tax planning strategies. 
  
  *Restricted Share Unit (RSU) Plan*
  We record outstanding RSUs as liabilities, measuring the liabilities and 
  compensation costs based on the award’s fair value, and recording it as 
  a charge to operating costs over the vesting period of the award. If the 
  award’s fair value changes after it has been granted and before the 
  settlement date, we record the resulting changes in the liability as a 
  charge to operating costs in the year that the change occurs. The 
  payment amount is established as of the vesting date. 
  See note 9 for more information about our income taxes. 