if the following are true:

• Expression Stack at time t = [ [ ], [ [ super(), ys ], rest ] ]
• Value Stack at time t = [ [ ], [ next_level, other_levels ] ]
• Control Map at time t = [ entry 0: (pair ("class", class_name)), [ entry 1: (pair ("method", method_name)), [ ] ] ]
• definition of method method_name of class class_name in (Class Map at time t) = method_map
• value at "params" in map method_map = [ param_name, other_params ]
• value at param_name in map (Variables Map at time t) = Python reference pi

then Expression Stack at time (t + 1) = [ ys, rest ]