[...] by a ‘definition’ is understood a partition of a sign-content or of a sign-expression.
- Hjelmslev (1961), a pag.72

Linguistic theory, whose main task is to make explicit the specific premisses of linguistics as far back as possible, sets up for that purpose a system of definitions [...] The aim is thus in practice to define as much as possible and to introduce premised definitions before those that premise them.
- Hjelmslev (1961), a pag.20