if the following are true:

• expression state at time 17 = "iterate_args"
• arguments stack at time 17 = [ [ 9, [ ] ], [ ] ]
• parent stack at time 17 = [ __eq__(7, 9), [ ] ]

then parent stack at time 18 = [ __eq__(7, 9), [ ] ]

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