Re: Bijections (was OM = SIGMA1)

2007-11-15 Thread Bruno Marchal
Le 14-nov.-07, à 17:23, Torgny Tholerus a écrit : Bruno Marchal skrev: 0) Bijections Definition: A and B have same cardinality (size, number of elements) when there is a bijection from A to B. Now, at first sight, we could think that all *infinite* sets have the same cardinality,

Re: Bijections (was OM = SIGMA1)

2007-11-15 Thread Torgny Tholerus
Bruno Marchal skrev: Le 14-nov.-07, 17:23, Torgny Tholerus a crit : What do you mean by "..."? Are you asking this as a student who does not understand the math, or as a philospher who, like an ultrafinist, does not believe in the potential infinite (accepted by

Re: Bijections (was OM = SIGMA1)

2007-11-15 Thread Quentin Anciaux
Hi, Le Thursday 15 November 2007 14:45:24 Torgny Tholerus, vous avez écrit : Bruno Marchal skrev: Le 14-nov.-07, à 17:23, Torgny Tholerus a écrit : What do you mean by each x here? I mean for each natural number. What do you mean by each in the sentence for each natural number?  How