I really have always wished for reproducibility. Thanks for taking up this feature. How do you handle aliasing and references inside objects? Suppose I have

    #Cell 1
    a = [1,2,3]
    b = (a,True)

    #Cell 2
    b[0][0] = 5

    #Cell 3
    print(sum(a))

Now if I change Cell 2 to

   # Cell 2'
   b[0][0] = 4

and execute, Cell 3's result becomes stale. Do you track such dependencies? Would really love to read more about the underlying implementation.