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:Now that [[User:Baccala@freesoft.org|Baccala@freesoft.org]] mentions it, it does make sense. I wrote that line in because I remember reading it in one of the introductory articles on computer algebra, but I have never read Richardson's result. These things can be tricky, and given that I am not a professional in computer algebra, I agree with the removal. [[User:XaosBits|XaosBits]] 17:46, 14 January 2006 (UTC)
: I found the reference. It's from Moses (of [[Macsyma]] fame) paper, ''Symbolic integration: the stormy decade'', in Communications of the ACM, volume 14. The quote about deciding if an expression is zero in on page 557. [[User:XaosBits|XaosBits]]
OK, thanks, I've looked over that reference now. It would seem to me that 1) I was wrong, and 2) the original statement was not entirely correct. My argument above only works if you can figure out if an extension is algebraic or transcendental to begin with, which seems to be the problem. Moses says "There exists no known general algorithm for determining whether a constant involving exponentials and logarithms is 0" (p. 557). But I still don't think Richardson's theorem applies here — there ''might'' be such an algorithm; I don't think it's been proven undecidable. I'll go read Richardson's paper in detail before I say more.
[[User:Baccala@freesoft.org|Baccala@freesoft.org]] 21:49, 26 January 2006 (UTC)
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