I'm trying to find out whether Tutte's conjecture (that every snark has the Peterson graph as a minor) has been satisfactorily proved. [Wikipedia][1] claims that Robertson, Saunders, Seymour and Thomas announced a proof but that it has not been published. Indeed, I cannot find a published paper which confirms the proof of the theorem.

Does anyone know what the status of this conjecture and proof are?
Thanks!


  [1]: https://en.wikipedia.org/wiki/Snark_(graph_theory)#Snark_theorem