the chicken and egg question

The chicken and egg come at the same time.

Proposition 0 A chicken is an animal that must be able to lay eggs, either directly or indirectly.

Theorem 0 If there are somethings such that they are called chicken and egg respectively, then they come in the world at the same time.

Proof We prove by contradiction and assume: If there are somethings such that they are called chicken and egg respectively, then they do not come in the world at the same time. Since the two things do not come in the world at the same time, the fist chicken must not lay the first egg, i.e. the first so called chicken will not lay any eggs and then, by Proposition 0, must not be a chicken. That is to say a chicken is not a chicken, which is contradiction. ◼