Fixed the absence of the nodes attribute in simplified node copying.
Fixed the builtins, removing artifacts of list-based tuples and other historical
mechanisms.
1l=[(0,10),(10,20)] 2y=23 3fora,binl: 4foriina,b: 5x=i 6else:# NOTE: Need to support StopIteration! 7x=y 8else: 9a=b