An axiom is defined as a statement or proposition which is regarded as being established, accepted, or self-evidently true.
Euclid′s Axioms (or Common Notions) Axiom 1− Things which equal the same thing also equal one another. Axiom 2− If equals are added to equals, then the wholes are equal. Axiom 3− If equals are subtracted from equals, then the remainders are equal. Axiom 4− Things which coincide with one another equal one another. Axiom 5− The whole is greater than the part.