In subordinate clauses, the action expressed by the present may be (a) contemporaneous, (b) antecedent, or (c) subsequent to that set forth by the main verb. The context alone decides in which sense the present is to be taken: (a)
ἔλεγεν ὅτι ἕτοιμος εἴη ἡγεῖσθαι αὐτοῖς
ἐστὶ τοῦ βασιλέος
ὡς δὲ γίγνονται ἐπ' αὐτῷ, ἐσπί_πτουσιν
ἐγένετο ῥήτρα_ . . . εἰ παρὰ ταῦτα ποιοῖεν, κολάζειν
Herbert Weir Smyth [n.d.], A Greek Grammar for Colleges; Machine readable text [info] [word count] [Smyth].