clone #5 summarizing means clones 1-4 never actually have the ideas, but cannot contribute any further to the solution-space beyond claiming they had those ideas. This doesn't create an additive effort to deriving a desired answer from the available solutions-space of your problem.
By "keying" I mean something that informs other iterations of the idea you're currently having and its invalidity without telling them the idea. "The thought I had at 5:14 -- it won't work. Move on."
This allows all six iterations to contribute towards deriving a viable answer without running into loops which require recursion to reach a stable state, which seems to be the kinds of loops that the Turners don't allow. (Helping a previous version's okay as long as they don't know where the help is coming from; but factoring integers instantly is not.)
I see. So I guess there is some benefit gained from this, but it is very minor. It seems to me that the simplest rule that explains why Harry's integer factorization is not okay, but, for example, the "silver on the tree" password from the end of TSPE is okay, is the following: if you would gain information at time T, and send information from time T to any time S < T, then it must be the case that you would have gained that same information even if you hadn't learned it at time S.
Now consider your "keying" scenario. We have clones ...
EDIT: New discussion thread here.
This is a new thread to discuss Eliezer Yudkowsky's Harry Potter and the Methods of Rationality and anything related to it. With two chapters recently the previous thread has very quickly reached 500 comments. The latest chapter as of 17th March 2012 is Ch. 79.
There is now a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author's Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
The first 5 discussion threads are on the main page under the harry_potter tag. Threads 6 and on (including this one) are in the discussion section using its separate tag system. Also: one, two, three, four, five, six, seven, eight, nine, ten.
As a reminder, it's often useful to start your comment by indicating which chapter you are commenting on.
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: