OK. Just a quick one. There seems to be an interesting analogy between the different layers in the BKO scheme.
Take the BKO:
|y> => op4 op3 op2 op1 "" |x>
which simply corresponds to stepping from superposition to superposition, then storing it in |y>
Well, a level above that, we have something similar with .sw files. Noting that just loading an sw file can do computation (the only time they don't is if all the rules are literal superpositions).
So the analogy of the above, at the sw level is:
Anyway, I just thought it was an interesting little observation.