The Abelian property or commutative property.
symmetric property of equality
Symmetric Property of Addition
Assuming that there is no significance in the first X being upper case and the second in lower case, it is an IDENTITY.
The zero property because it has a zero.
Commutative property of addition of numbers.
5 x 4 equals 4 x 5 is commutative property.
x + y + z = x + z + y is the commutative property of addition.
The distributive property of multiplication over addition.