ἐν πέτροισι πέτρον ἐκτρίβων → by grinding stone against stones
ᾰπήνα mule chariot ἀκαμαντόποδός τ' ἀπήνας δέκευ ψαύμιός τε δῶρα (O. 5.3) ἀνὰ δ' ἡμιόνοις ξεστᾷ τ ἀπήνᾳ (P. 4.94)
