Compositional etymology, which has its source in the Homeric line ὥ τ’ ὀλίγῳ ἐνὶ χώρῳ ἐρίζητο<ν> περὶ ἴσης (Il. 12.423) "and the two of them fight in the strait place over the rights of division" (transl. Huddleston). From there the aorist infinitiveἔρισαι was analyzed as ἔρ-ισαι, from ἔρα and ἴσος. It is quite uncommon for Greek etymologists to start from the aorist infinitive in order to etymologize a verb: this is clearly because the Homeric ἴσης required an aorist form in -ισα, and the aorist provided the sequence -ισαι, which coincides with a real case form of the etymon, viz. the nominative plural. Notice that neither of the two etymons mean "quarrel" or "contest": the etymon means "equal earth". Only in the Homeric line could it be though to be a proper etymon for ἐρίζω, since the Homeric line associates ἐρίζω and ἴση. This etymology was in turn erroneously understood and gave risotto the reverse etymology deriving ἔρα from ἐρίζω (see ἔρα / ἐρίζω). The wording in the Gudianum does not make it clear that it is a compositional etymology, since only the first etymon, ἔρα, is mentioned. Therefore, it could be considered as a derivational etymology. However, the compositional etymology is explicit in the Et. Magnum, and we can assume that the Gudianum's wording is a shortened form of this etymology