mathguy
Posts:
12
Registered:
6/23/13


Re: number problem
Posted:
Jun 30, 2013 12:52 PM


On Friday, June 28, 2013 2:53:21 PM UTC7, quasi wrote: > japonishi wrote: > > > > >you math practitioners clearly have an abstract definition about > > >what is a set.. for us ordinary people, a box of identical paper > > >clips is a set of identical clips, period, > > > > Identical as far as appearance (at least approximately) and > > functionality (they are interchangeable as far as their intended > > purpose) but they are _not_ physically identical. Do they have > > the same atoms? Certainly not. Thus, the clips are physically > > distinct, even you regard them (from your point of view as clip > > user) as indistinguishable. > > > > >so what I(we) call a set of numbers is just a collection of > > >numbers, which may be distinct or repeated. > > > > In mathematics, by agreement, sets do not allow for elements > > to be counted more than once. If you need to consider repeated > > elements, a sequence is a more appropriate structure. > > > > >i'm no fan of your abstract sets, > > > > And yet you initially posted using the handle "mathguy". > > > > >but thanks for clarifying the issue. > > > > You're welcome. > > > > Note that when the Olympiad problem used the terminology > > "a set of n elements", it was intended in the pure math sense. > > Thus the problem can't be trivially solved in the way you > > suggested, when you gave the example set {0,2,2,2,2,4}, > > which you initially claimed to be a set of 6 elements. > > > > quasi
first of all, i'm no mathematician, just someone with recreational math interest, nothing wrong with "mathguy" as a handle, and i don't comment about your "quasi" handle, so be respectful of others. So for me(us), {0,2,2,2} is still a set of 4 elements, whether you like it or not. only when talking to hardcore maths should i refer to "multisets" or "sequences" or "lists" etc. what do i care if paper clips are physically distinct, as in atomically distinct, all i care is they're functionally identical. 2 and 2 = 4, not 2.

