We do know that Ptolemy used observations made by 'Theon the mathematician', and this was almost certainly Theon of Smyrna who almost certainly was his teacher.
Namin gawin kung Ptolemy na ginamit obserbasyon na ginawa sa pamamagitan ng 'Theon ang dalubbilang', at ito ay halos tiyak Theon ng Smyrna na halos tiyak ay kanyang guro.