Thought:
even though we assigned a P2 to 70, in order to get the PP2,
when it then comes to testing the upper OB level, are we in effect testing 70 in relation to a T1 (69) ?
If so, P1 is killed after a T1 ?
So Jack assigned P2 for upper OB ?
TI is killed after P2 so he assigned P1 for lower...