noZeroTurns tr =
  case trTotals tr of
    Nothing -> isNotZero (trCredit tr) || isNotZero (trDebit tr)
    Just t  -> isNotZero t
noZeroTurns tr =
  case trTotals tr of
    Nothing -> isNotZero (trCredit tr) || isNotZero (trDebit tr)
    Just t  -> isNotZero t
noZeroTurns tr =
  case trTotals tr of
    Nothing -> isNotZero (trCredit tr) || isNotZero (trDebit tr)
    Just t  -> isNotZero t