Commutative Law of Addition

Theorem
On all the number systems: the operation of addition is commutative.
 * natural numbers $$\N$$
 * integers $$\Z$$
 * rational numbers $$\Q$$
 * real numbers $$\R$$
 * complex numbers $$\C$$

Proof
This is demonstrated in these pages:


 * Natural Number Addition is Commutative
 * Integer Addition is Commutative
 * Rational Addition is Commutative
 * Real Addition is Commutative
 * Complex Addition is Commutative