Subject: RE: [xsl] A nice way to implement the ANDing of the comparison of pairs of items in a sequence?|
From: "Costello, Roger L." <costello@xxxxxxxxx>
Date: Fri, 6 Sep 2013 11:33:05 +0000
> 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.