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I emailed back and forth with Leslie a lot about this, when I first read his paper. There is an earlier analysis of the same phenomenon by different people (the arbiter problem) which I discovered later.

At first, I had trouble to believe it, and tried to find counterexamples, until I realized that the composition of continuous functions is continuous. I still wonder sometimes whether an infinite composition of continuous functions has to be continuous (limit of a sequence) if it represents some real world evolving process. Can it produce a discontinuity in the limit?

Anyway, Buridan’s principle informs our consensus process in Intercoin Protocol[1] [2] — it is why the consensus groups are always of a bounded finite size, so we don’t approach the errors in Buridan’s priciple (I think this is also called unstable problems).

1. Beyond blockchains https://community.intercoin.org/t/intercoin-technology-conse...

2. Experimental improvements https://community.intercoin.org/t/experimental-improvements-...

Anyone who reads the above … I would be very interested in your feedback on our forum.




> I still wonder sometimes whether an infinite composition of continuous functions has to be continuous (limit of a sequence) ...

No, as you expected. Take f(x) = x^2 on [0,1]. Then f(f(f(...f(x))) converges to g(x) = { 0, if 0 <= x < 1; 1, if x=1 }


Right. So now the question is -- are you able to give a physical example of physical (continuous) processes which can create a discontinuous output from a continuous initial state, in a finite amount of time? I think this is a sort of Zeno's paradox...


Tossing a coin?


No. The coin could land on its side, for instance, and stay there.

Consider a pencil that is placed almost vertically, and then later drops to a horizontal position. There is a period where it is "unsure" where to go, and the more perfectly balanced it starts out, the longer this period is (assuming no wind etc.)

That's what is being discussed.




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