περὶ δὲ τῶν ἀρχῶν, πῶς τε γίνονται γνώριμοι καὶ τίς ἡ γνωρίζουσα ἕξις, ἐντεῦθεν ἔσται δῆλον.
Now for the principles: How they become known and what hexis makes [them] known will become clear after we lay down the problems.
The subject is compound—“how they become known” and “what makes them known”—but the verb ἔσται is singular. Right? In ancient Greek can a singular, instead of plural, verb be used with a compound subject? Am I misreading?
Or is there an implied singular subject, something like “Now [for the issue of] principles (how they become known and what hexis makes them know): it will become clear . . .”