177. In certain cases, viz. when the verb is understood, a preposition may represent the whole predicate of a clause.
οἰωνοὶ δὲ πέρι πλέες ἠὲ γυναῖκες
abοut (him) are more, etc.
ἔνθʼ ἔνι μὲν φιλότης
therein is love
οὔ τοι ἔπι δέος
there is nο fear for you
ἀλλʼ ἄνα
but up!
πάρα δʼ ἀνήρ
the man is at hand
πάρ ἔμοιγε καὶ ἄλλοι
others are at my command
(not are beside me, but = πάρεισι in its derived sense)
So when a verb is to be repeated from a preceding clause.
Il. 24.229-233 ἔνθεν δώδεκα μὲν περικαλλέας ἔξελε πέπλους . . . ἐκ δὲ δύʼ αἴθωνας τρίποδας
Il. 3.267 ὤρνυτο δʼ αὐτίκʼ ἔπειτα ἄναξ ἀνδρῶν Ἀγαμέμνων, ἂν δʼ Ὀδυσεύς (sc. ὤρνυτο)