Theaet, 146b

[Constantinus Philo]

τοῖσδε δὲ πρέποι τε ἂν τοῦτο καὶ πολὺ πλέον ἐπιδιδοῖεν:
it would befit those to progress in this even on a greater scale. Is this translation correct?

[PastelKos]

Hello!
ἐπιδιδοῖεν is not connected with πρέποι but is a seperate optative with an understood ἂν missing (πρέποι ἂν καὶ ἐπιδιδοῖεν ἄν). I would translate it thus:
but that would be fitting to these and they would progress/improve much more

[Constantinus Philo]

of course you are right but if I say τοῖσδε δὲ πρέποι τε ἂν τοῦτο καὶ πολὺ πλέον ἐπιδιδόναι will it be good greek