Characteristic
From Conservapedia
In algebra, the characteristic of a ring R is the least natural number n such that, for all r in R, n * r = 0. If no such natural number exists, the ring has characteristic 0. The characteristic of a field must be either 0 or a prime number.
Examples
- - the set of the integers - has characteristic 0.
- has characteristic 6:
0 = 0 = 0+0+0+0+0+0 1+1+1+1+1+1 = 0 = 1+1+1+1+1+1 2+2+2 = 0 = 2+2+2+2+2+2 3+3 = 0 = 3+3+3+3+3+3 4+4+4 = 0 = 4+4+4+4+4+4 5+5+5+5+5+5 = 0 = 5+5+5+5+5+5
- If R is a ring with unity, i.e., there exists a multiplicative identity 1, then the characteristic is already given by the smallest r such that r * 1 = 0. If no such r exists, the characteristic is defined as zero.