ποταμῷ γὰρ οὐκ ἔστιν ἐμβῆναι δὶς τῷ αὐτῷ → it is impossible to step twice in the same river, you cannot step twice into the same rivers
κατατήκω, κατατάκω, σήπω, διαλύω, διακρίνω, συσσήπω, ἀναλύω, ἀλλύω, τήκω, τάκω