x = x + x

y = y * y

z + z = z * z

Results 16 to 22 of 22

- October 16th 2012, 02:14 PM #16

- Joined
- Aug 2010
- Posts
- 961
- Thanks
- 98

## Re: What is a 2?

The bean analogy is simply the basis of Peano's axioms, in intuitive (but accurate) terms. "zero" is an empty pot, etc.

The correspondence between 2 of anything is quite natural. If one cave man asked another how many arrows he had, if he put two beans in a pot I think the other would understand. That is 2.

- October 30th 2012, 05:21 AM #17

- Joined
- May 2010
- Posts
- 11
- Thanks
- 1

- November 12th 2012, 05:11 PM #18

- Joined
- Apr 2005
- Posts
- 17,904
- Thanks
- 2327

## Re: What is a 2?

Cute! Took me a few minutes to figure out what meant but I finally got it:

"x= 0" is the number satisfying x= x+ x.

"y= 1" is the number satisfying y= y*y.

"z= 2" is the number satisfying z+ z= z*z.

However, I have to point out that 0= 0*0 and 0+ 0= 0*0 also.

- November 12th 2012, 05:57 PM #19

- Joined
- Sep 2012
- From
- Planet Earth
- Posts
- 217
- Thanks
- 56

- November 13th 2012, 07:32 AM #20

- Joined
- Aug 2010
- Posts
- 961
- Thanks
- 98

- November 13th 2012, 05:28 PM #21

- Joined
- Mar 2011
- From
- Tejas
- Posts
- 3,546
- Thanks
- 842

## Re: What is a 2?

true enough, but one could define + and * as the ring operations of the initial object in the category of all (small) rings. presumably, "=" needs little explanation.

then we have:

(y+y) + (y+y) = y + y + y + y = y*y + y*y + y*y + y*y = y*(y+y) + y*(y+y) = (y+y)*(y+y)

indicating that z = y+y is "a" solution to z+z = z*z.

an interesting question: can one give examples of a ring R where 1+1 ≠ 0, but there is a solution to z+z = z*z besides 0 and 1+1?

- November 14th 2012, 08:52 AM #22

- Joined
- Aug 2010
- Posts
- 961
- Thanks
- 98

## Re: What is a 2?

Thanks for your reply. Your question* is interesting but no more relative to original question than 2 is the solution of x^2=4.

*"an interesting question: can one give examples of a ring R where 1+1 ≠ 0, but there is a solution to z+z = z*z besides 0 and 1+1?" One might give matrices or complex numbers a try.

EDIT: Personally, I thought posts 14 & 16 were the best replies to the original question.