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Re: [xsl] A nice way to implement the ANDing of the comparison of pairs of items in a sequence?


Subject: Re: [xsl] A nice way to implement the ANDing of the comparison of pairs of items in a sequence?
From: Wolfgang Laun <wolfgang.laun@xxxxxxxxx>
Date: Fri, 6 Sep 2013 16:30:30 +0200

Anybody who can - today - multiply an 9-digit number with a 12-digit
number on the blackboard and come up with the correct result would
IMHO deserve a standing ovation, too. :-)

Cheers

On 6 September 2013 13:33, Costello, Roger L. <costello@xxxxxxxxx> wrote:
>> How about
>>
>> deep-equal($v[position() mod 2 = 0], $v[position() mod 2 = 1])
>>
>> Michael Kay
>
> That, sir, deserves a standing ovation.
>
> The succinctness and power of Michael's response reminds me of a story I
recently read:
>
> The Lecture Without Words
>
> At the meeting of the American Mathematical Society in 1903 the
mathematician Frank Nelson Cole gave a "lecture without words," silently
performing the multiplication
>
> 193 707 721 * 761 838 257 287 = 147 573 952 588 676 412 927
>
> on the blackboard. The number on the right-hand side is 2^67 - 1, which the
17th-century French mathematician Marin Mersenne conjectured is prime. In
1876, Edouard Lucas managed to prove that it is composite, but gave no
indication of what numbers would divide it. The audience, knowing full well
how hard it is to factor 21-digit numbers, greeted Cole's presentation with a
standing ovation.


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