Integers form Subdomain of Rationals

Theorem
The integral domain of integers $$\left({\Z, +, \times}\right)$$ forms a subdomain of the Field of Rational Numbers.

Proof
The rational numbers are defined as the quotient field of the integers.

From its method of construction, it follows that the integers $$\Z$$ are a subset of the rational numbers $$\Q$$.

Hence the result, from the definition of subdomain.