an agnostic is one who claims to have proof of the nonexistance of God
quote:
1.
a. One who believes that it is impossible to know whether there is a God.
b. One who is skeptical about the existence of God but does not profess true atheism.
2. One who is doubtful or noncommittal about something.
thefreedictionary
quote:
Agnosticism (from the Greek a, meaning "without", and gnosticism or gnosis, meaning "knowledge") is the philosophical view that the truth value of certain claims”particularly metaphysical claims regarding theology, afterlife or the existence of God, gods, deities, or even ultimate reality”is unknown or, depending on the form of agnosticism, inherently unknowable due to the nature of subjective experience.
Agnostics claim either that it is not possible to have absolute or certain knowledge of the existence or nonexistence of God or gods; or, alternatively, that while individual certainty may be possible, they personally have no knowledge. Agnosticism in both cases involves some form of skepticism.
Wikipedia
I have never heard of an Agnostic that has such certainty, care to provide a quote - and then explain how it fits with the definition of agnosticism?
I claim you have no proof that I have proof.