but simply an archaic pronunciation. Another example is . A complex example of epenthesis is , from + . It exhibits epenthesis on both morphemes: → is common (occurring before a consonant), and → occurs only in the example; it can be analyzed as → (intervocalic) → ; akin to from + . One hypothesis argues that Japanese developed "as a default, epenthetic consonant in the intervocalic position". Anaptyxis Epenthesis of a vowel is known as anaptyxis (, from Greek "unfolding"). Some accounts distinguish between "intrusive" optional vowels, vowel-like releases of consonants as phonetic detail, and true epenthetic vowels that are required by the phonotactics of the language and are acoustically identical with phonemic vowels. Historical sound change End of word Many languages insert a so-called prop vowel at the end of a word, often as a result of the common sound change where vowels at the end of a word are deleted. For example, in the Gallo-Romance languages, a prop schwa /ə/ was added when final non-open vowels were dropped leaving /Cr/ clusters at the end, e.g. Latin nigrum '(shiny) black' > * > Old French negre 'black' (thus avoiding the impermissible , cf. carrum > char 'cart'). Middle of word Similarly as above, a vowel may be inserted in the middle of a word to resolve an impermissible word-final consonant cluster. An example of this can be found in Lebanese Arabic, where /ˈʔalɪb/ 'heart' corresponds to Modern Standard Arabic /qalb/ and Egyptian Arabic /ʔælb/. In the development of Old English, Proto-Germanic 'field, acre' would have ended up with an impermissible final cluster (*æcr), so it was resolved by inserting an /e/ before the rhotic consonant: (cf. the use of a syllabic consonant in Gothic ). Vowel insertion in the middle of a word can be observed in the history of the Slavic languages, which had a preference for open syllables in medieval times. An example of this is the Proto-Slavic form 'town', in which the East Slavic languages inserted an epenthetic copy vowel to open the closed syllable, resulting in (), which became () in modern Russian and Ukrainian. Other Slavic languages used metathesis for the vowel and the syllable-final consonant, producing *grodŭ in this case, as seen in Polish , Old Church Slavonic градъ gradŭ, Serbo-Croatian and Czech . Another environment can be observed in the history of Modern Persian, in which former word-initial consonant clusters, which