Roberval and Étienne Pascal became involved in the argument and eventually so did Desargues who Descartes asked to act as a referee. Fermat proved correct and eventually Descartes admitted this writing:
Roberval at Etienne Pascal ay naging kasangkot sa argument at sa huli kaya ay Desargues na Descartes hingin sa iyo na kumilos bilang isang reperi. Fermat proved tama at sa huli Descartes natanggap na ito pagsulat: