Puzzles, state diagrams, sequence control

[From Bruce Abbott (951112.1240 EST)]

Bill Powers (951112.0805 MST) --

Bruce Abbott --

I'm commenting on your rubber-band post direct to you, to give others a
chance to try before discussing answers.

Just to keep the suspense from killing anyone, I'll admit that I made some
mistakes. What is interesting (to me anyway) is why.

Re: State diagrams

                   A state diagram of a program

                                     diagram represents a program
Does state diag include a choice?
                                     diagram represents a sequence

Moving from one state to another must require at least one decision: has
whatever was supposed to happen in the current state happened? If so, move
to next state. On the other hand, WHICH state to move TO may or may not
involve a choice. If it doesn't, then would the state diagram represent a

I can visualize a mechanism that, say, fires three blasting caps in sequence
via a timer. If the first cap failed to fire, the timer would continue
anyway, triggering the second and then the third cap.

Another mechanism might trigger the first cap, then trigger the second on
receiving feedback (e.g., blast pressure-wave) that the first had fired, etc.

Would both be considered sequences in your scheme? Do both kinds of
mechanism exist among our various control systems?

I'll be looking for your sequel.