The challenge lies in the nature of the raw "material" myth. If myth is a special kind of plot-like raw material or (Erzähl-)Stoff (see above) and not a text or a picture etc., one has first to find a way to work with them and to analyse them, since they are not identical to a single textual or a pictorial representation. In order to analyse them one needs a methodological basis. This can be reached through extracting and reconstructing the smallest action-bearing units from mythical texts (or pictures or other medial concretizations), as C. Zgoll 2019 shows. These smallest action-bearing units are called "hylemes", in the case of myths "mythical hylemes" (from greek "hyle" = "material" or "Stoff", cf. ling. "phoneme"). These hylemes are to be determined in a formal way.
The so-defined mythical hyleme is something very different from the "mytheme" of Lévy-Strauss, who combines several hylemes and calls only a "bundle" of hylemes a "mytheme" (1971 [1958]: 231), for him a meaning-bearing unit of a myth, where meaning is conceived in terms of his theory of binary semantic opposites (cf. Lévi-Strauss 1963, 210-211). A mythical hyleme is functionally indeterminate and as such different as well from the approach of Propp 1928, who analyses sequences of fairy-tales under a functional perspective and speaks of "functions".