A bit of combinatorial trivia: you can define a multiplication on matrices of natural numbers using gcd for multiplication and lcm for addition. The identity matrix has zeros on the diagonal and ones off the diagonal. On Mon, Feb 10, 2014 at 11:16 AM, Dan Asimov <dasimov@earthlink.net> wrote:
Wikipedia implies that the characteristic of a ring R (with unity) can be defined as the unique nonnegative integer such that nZ is the kernel of the ring homomorphism h:Z -> R (with h(1) = 1). Any field is also a ring, so this can be applied, making characteristic 0 a non-hack.
--Dan
On 2014-02-10, at 6:41 AM, Henry Baker wrote:
Yes, 0 is the ultimate composite number. The use of the phrase "characteristic zero" is merely a hack, and nothing should be read into this usage.
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