bad_stm_example1.scala

atomic{ implicit t =>
  var accounts = accountsRef()
  val (from, to) = (accounts(fromNo), accounts(toNo))
  if(from.balance > amount){
    accounts = accounts + (to.accountNo -> to.credit(amount))
    accounts = accounts + (from.accountNo -> from.debit(amount))
    accountsRef() = accounts
    applyTransferFees()
  }
}