if the following are true:

• expression state at time 54 = "iterate_args"
• arguments stack at time 54 = [ [ 5, [ ] ], [ [ ], [ ] ] ]
• parent stack at time 54 = [ __add__(self.x, 5), [ self."x" = __add__(self.x, 5), [ ] ] ]

then parent stack at time 55 = [ __add__(self.x, 5), [ self."x" = __add__(self.x, 5), [ ] ] ]

Start from the conclusion and work back up the proof. Click the arrow to show the parents.