Equality is Equivalence Relation

Theorem
Equals is an equivalence relation.

Proof
This follows from the Axioms of Equality:


 * Reflexive: $$\forall a: a = a$$.
 * Symmetric: $$\forall a, b: a = b \implies b = a$$.
 * Transitive: $$\forall a, b, c: a = b \land b = c \implies a = c$$.