Arthur Prior asserts that there is nothing paradoxical about the liar paradox. Supposed paradoxes involving infinite series, such as Zeno's paradox, predated Euclid. There are many theories to explain the apparent paradox. A parallel phenomenon is known as the French Paradox. There are various ideas about how the paradox is solved. He proved the eternal paradox of things. This phenomenon is known as the "paradox of aging". It is one of many theoretical explanations for the Fermi paradox. Some advocate a parallel universe approach to the grandfather paradox. This problem is treated at much greater length in the birthday paradox. Various theorists have suggested weakening the IIA criterion as a way out of the paradox. There are two ways of resolving this paradox. This entire situation is very similar to the Tea leaf paradox. Horii liked the scenario of the grandfather paradox surrounding Marle. This is famous as the friendship paradox.