try:

	from Numeric import add, subtract, maximum

except ImportError:

	import operator
	
	def add(x, y):
		return map(operator.add, x, y)
	
	def subtract(x, y):
		return map(operator.sub, x, y)
	
	def maximum(*args):
		result = args[0]
		for x in args[1:]:
			result = map(max, result, x)
		return result
