Didn't know that stuff! Many thanks, Adam! Best, É. -----Message d'origine----- De : math-fun-bounces@mailman.xmission.com [mailto:math-fun-bounces@mailman.xmission.com] De la part de Adam P. Goucher Envoyé : mardi 13 décembre 2011 18:33 À : math-fun Objet : Re: [math-fun] A Xmas present
Six, one, eight, five, two, seven, four, ten, one, two, two, three, seven, zero, close.
Ask the kids to draw a thin vertical stroke after each letter "e". Count the letters between the strokes. Enjoy!
That's a solution of the Post correspondence problem over the words: xxe|e xxx|xe xxxee|xxe xxxx|xxxe xxxe|xxxxe xxx|xxxxxe xexex|xxxxxxe exxxx|xxxxxxxe xxxe|xxxxxxxxe xex|xxxxxxxxxe xexxxxxxe| As well as the restriction that the fnal word ('zero close') appears once at the end of the string. http://en.wikipedia.org/wiki/Post_correspondence_problem Sincerely, Adam P. Goucher _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun