Zero Divides Zero

Theorem

Let $n \in \Z$ be an integer.


Then:

$0 \divides n \implies n = 0$

That is, zero is the only integer divisible by zero.


Proof

\(\ds 0\) \(\divides\) \(\ds n\)
\(\ds \leadsto \ \ \) \(\ds \exists q \in \Z: \, \) \(\ds n\) \(=\) \(\ds q \times 0\) Definition of Divisor of Integer
\(\ds \leadsto \ \ \) \(\ds n\) \(=\) \(\ds 0\) Integers have no zero divisors, as Integers form Integral Domain.

$\blacksquare$


Sources

  • 1969: C.R.J. Clapham: Introduction to Abstract Algebra ... (previous) ... (next): Chapter $3$: The Integers: $\S 10$. Divisibility
  • 1982: P.M. Cohn: Algebra Volume 1 (2nd ed.) ... (previous) ... (next): Chapter $2$: Integers and natural numbers: $\S 2.2$: Divisibility and factorization in $\mathbf Z$
  • 1994: H.E. Rose: A Course in Number Theory (2nd ed.) ... (previous) ... (next): $1$ Divisibility: $1.1$ The Euclidean algorithm and unique factorization: $\text {(ii)}$