if the following are true:

• Parameters List at time t = [ ]
• Expression Stack at time t = [ [ ], [ [ obj_name.method_name(args), ys ], rest ] ]
• value at obj_name in map (Variables Map at time t) = Python reference index
• the element at index index of stack (Python Object Store at time t) = Python object: [ entry "__class_name__": class_name, e_rest ]
• line number of method method_name of class class_name in (Class Map at time t) = line

then the line at time (t + 1) = line + 1