Phonology
(3) is an example of an implicational hierarchy concerning the distribution of nasal phonemes across languages, which concerns dental/alveolar, bilabial, and palatal voiced nasals, respectively:
(3) /n/ < /m/ < /ɲ/
This hierarchy defines the following possible combinations of dental/alveolar, bilabial, and palatal voiced nasals in the phoneme inventory of a language:
(4)
| /n/ | /m/ | /ɲ/ | |
|---|---|---|---|
| Type 1: | /n/ | /m/ | /ɲ/ |
| Type 2: | /n/ | /m/ | - |
| Type 3: | /n/ | - | - |
In other words, the hierarchy implies that there are no languages with /ɲ/ but without /m/ and /n/, or with /ɲ/ and /m/ but without /n/.
Read more about this topic: Implicational Hierarchy