if the following are true:

• expression state at time 13 = "iterate_args"
• arguments stack at time 13 = [ [ "Smith", [ 25, [ ] ] ], [ ] ]
• parent stack at time 13 = [ Person("John", "Smith", 25), [ ] ]

then parent stack at time 14 = [ Person("John", "Smith", 25), [ ] ]

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