τοιαῦτ᾽ ἄττα ἐστίν, οἶμαι, ὦ Κέβης, ἃ λέγεις· καὶ ἐξεπίτηδες πολλάκις ἀναλαμβάνω, ἵνα μή τι διαφύγῃ ἡμᾶς, εἴ τέ τι βούλει, προσθῇς ἢ ἀφέλῃς. These two subj look delib after
βούλει And not final as Burnet says. Phaed 95e
Otherwise there is elision of ινα
You should think twice before disagreeing with Burnet—or simply think. προσθῇς ἢ ἀφέλῃς is clearly dependent on ἵνα, just as μή τι διαφύγῃ ἡμᾶς is. You failed to take τε “and” into account, which links the two parts of the ἵνα clause, the one negative, the other positive. Your suggestion was nonsensical.
I can see it now thanx