1. Slide 5 has been expanded with new animations

2. Slide 20, now deals exclusively with two-index notation for voltages

3. slide 21 is new and uses figures 1.7 and 1.8 from the first-pass PDF

4. slide 22 now contains energy example previously in slide 20

5. slide 23 now contains energy example also from old slide 20

New slide 24 corresponds to old slide 21