Talk:Addition-chain exponentiation: Difference between revisions

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: That said, if you can modify the task in some reasonable way which brings out the flaws of star chains, I would accept your reasoning. --[[User:Rdm|Rdm]] ([[User talk:Rdm|talk]]) 21:43, 20 July 2015 (UTC)

::The article does not say it's the smallest counterexample. For you, if a statement is not (yet) proved, it's considered to be true? Wrong. Either you have a proof that star chains produce optimal solutions for 31415 and 27182, either a program based on star chain is useless. When the task asks for optimal solution, that means provably optimal solution, not ''maybe optimal, maybe not''. [[User:Arbautjc|Arbautjc]] ([[User talk:Arbautjc|talk]]) 21:56, 20 July 2015 (UTC)

Quoting [http://strangelyconsistent.org/blog/t3-addition-chains this]: '''" A Brauer-based algorithm will fail the first time at N = 12509]."''' (if this site is not enough for you, I'll try to give you the reference in Knuth's TAOCP then, as I'm sure to have read this in one of the volumes). It's far below the values of the task, which is a big problem for me. And the article linked in the Go program does not claim to give optimal solution, on the contrary: '''"Even though minimal-length cf-chains are not optimal, they have the nice property of being easy to compute [...]"'''.

This should close the question on the (in)correctness of the Go program.

[[User:Arbautjc|Arbautjc]] ([[User talk:Arbautjc|talk]]) 23:10, 20 July 2015 (UTC)