Commutative Law of Addition

Theorem
On all the number systems:


 * natural numbers $\N$
 * integers $\Z$
 * rational numbers $\Q$
 * real numbers $\R$
 * complex numbers $\C$

the operation of addition is commutative:


 * $a + b = b + a$

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