def executeLeftOperations(evaluators, operationLevel):
 for negativeIndex in xrange((- len(evaluators)), (-1)):
  evaluatorIndex = (negativeIndex + len(evaluators))
  evaluators[evaluatorIndex].executeLeftOperation(evaluators, evaluatorIndex, operationLevel)

def executeLeftOperations ( evaluators , operationLevel ) : for negativeIndex in xrange ( ( - len ( evaluators ) ) , ( - 1 ) ) : evaluatorIndex = ( negativeIndex + len ( evaluators ) ) evaluators [ evaluatorIndex ] . executeLeftOperation ( evaluators , evaluatorIndex , operationLevel )
evaluate the expression value from the numeric and operation evaluators .