Re: Searching for a function
- To: mathgroup at smc.vnet.net
 - Subject: [mg70850] Re: [mg70813] Searching for a function
 - From: Murray Eisenberg <murray at math.umass.edu>
 - Date: Sat, 28 Oct 2006 23:39:41 -0400 (EDT)
 - Organization: Mathematics & Statistics, Univ. of Mass./Amherst
 - References: <200610280921.FAA16103@smc.vnet.net>
 - Reply-to: murray at math.umass.edu
 
I don't understand your question.  If B is not empty, then there ALWAYS 
exists at least one function from A to B:  If A is empty, then the 
function with empty graph is a function from A to B; if A is nonempty, 
then any constant function with value an element of B is a function from 
A to B.
Bonny Banerjee wrote:
> Is it possible for Mathematica to solve this problem:
> 
> Given sets A and B, does there exist a function from A to B? If yes, what is 
> the function?
> 
> 
> Here is an example:
> 
> Let, A = {x such that 0<x<11 and Mod[x,2]==0}
> 
> B = {y such that 0<y<11 and Mod[y+1,2]==0}
> 
> Then, there exists a function from A to B
> 
> y = x - 1
> 
> 
> Thus, is there a way to specify arbitrary sets A, B, and use Mathematica to 
> figure out whether there exits a function from A to B or not?
> 
> Thanks,
> Bonny.
> 
> 
> 
-- 
Murray Eisenberg                     murray at math.umass.edu
Mathematics & Statistics Dept.
Lederle Graduate Research Tower      phone 413 549-1020 (H)
University of Massachusetts                413 545-2859 (W)
710 North Pleasant Street            fax   413 545-1801
Amherst, MA 01003-9305
- References:
- Searching for a function
- From: "Bonny Banerjee" <banerjee.28@osu.edu>
 
 
 - Searching for a function