# class Environment():
	
# 	def hasBinding(N):
# 		return False

# 	def createMutableBinding(N, D):
# 		return False


# class Environment():
	
# 	def hasBinding(N):
# 		return False

# 	def createMutableBinding(N, D):
# 		return False


# class Environment(): # 	def hasBinding(N): # 		return False # 	def createMutableBinding(N, D): # 		return False