David Lim wrote:ἁπλῶς δὲ τὰ ἄτομα καὶ ἓν ἀριθμῶ κατ' οὐδενὸς ὑποκειμένου λέγεται, ἐν ὑποκειμένῳ δὲ ἔνια οὐδὲν κωλύει εἶναι· ἡ γὰρ τὶς γραμματικὴ τῶν ἐν ὑποκειμένῳ ἐστίν.
Carl, can I ask why it is "η τις γραμματικη" with "τις" in the so-called attributive position? Is this construction also found in the later Koine Greek?
Because it's attributive, perhaps? γραμματική here is the substantive. It's worth looking at the lengthy entry on the indefinite τις, τι in LSJ. To be noted there is this paragraph:
— in Philosophic writers, τις is added to the Art. to show that the Art. is used to denote a particular individual who is not specified in the general formula, although he would be in the particular case, ὁ τὶς ἄνθρωπος the individual man ( whoever he may be), this or that man, opp. ἄνθρωπος (man in general), ὁ τὶς ἵππος, ἡ τὶς γραμματική, Arist.Cat.1b4, 8; τὸ τὶ μέγεθος, opp. ὅλως τὸ μέγεθος, Id.Pol.1283a4, cf. S.E.P.2.223; but in ἑνὸς γὰρ τό γε τὶ φήσεις σημεῖον εἶναι Pl.Sph.237d, the Art. is used as in Il. cc. s.v. ὁ, ἡ , τό B.1.5: later ὅ τις (or ὁ τὶς ) much like ὁ δεῖνα, δεῦρο ὅ τις θεός, ὄφθητί μοι in a general formula of invocation, PMag.Par. 1.236; αἴρω σε, ἥ τις βοτάνη ib.287; εἰς τήν τινα κρείαν (leg. χρείαν ) ib.289.