Old English phonology

Old English phonology is necessarily somewhat speculative since Old English is preserved only as a written language. Nevertheless, there is a very large corpus of the language, and the orthography apparently indicates phonological alternations quite faithfully, so it is not difficult to draw certain conclusions about the nature of Old English phonology.

Old English had a distinction between short and long (doubled) consonants, at least between vowels (as seen in sunne "sun" and sunu "son", stellan "to put" and stelan "to steal"), and a distinction between short vowels and long vowels in stressed syllables. It had a larger number of vowel qualities in stressed syllables – /i y u e o æ ɑ/ and in some dialects /ø/ – than in unstressed ones – /ɑ e u/. It had diphthongs that no longer exist in Modern English, which were /iu̯ eo̯ æɑ̯/, with both short and long versions.

Sound inventory

The inventory of surface sounds (whether allophones or phonemes) of Old English is as shown below. Allophones are enclosed in parentheses.

Consonants

Labial Dental Alveolar Post-
alveolar		 Palatal Velar Glottal
Nasal m (n̥) n (ŋ)
Stop p b t d k ɡ
Affricate tʃ (dʒ)
Fricative f (v) θ (ð) s (z) ʃ (ç) (x ɣ) h
Approximant (l̥) l j (ʍ) w
Trill (r̥) r

Intervocalic voicing

The fricatives /f θ s/ had voiced allophones [v ð z] between vowels or voiced consonants.

  • stæf ('letter') /ˈstæf/: [ˈstæf]
stafas ('letters') /ˈstɑfɑs/ > [ˈstɑvɑs]
  • smiþ ('blacksmith') /smiθ/: [ˈsmiθ]
smiþas ('blacksmiths') /ˈsmiθɑs/ > [ˈsmiðɑs]
  • hūs ('house' noun) /ˈhuːs/: [ˈhuːs]
hūsian ('house' verb) /ˈhuːsiɑn/ > [ˈhuːziɑn]
  • forþ ('forth') /ˈforθ/: [ˈforθ]
compare eorðe ('earth') /ˈeo̯rθe/ > [ˈeo̯rðe]
  • fæþm ('fathom') /ˈfæθm/ > [ˈfæðm]

Proto-Germanic *β, a fricative allophone of *b, developed into the OE fricative /f/ (or its allophone [v]) except when geminated, but PG *ð developed into the OE stop /d/.[1]

  • PG *stabaz /ˈstɑβɑz/ > OE stæf /ˈstæf/
  • PG *habjaną, *habdē /ˈhɑbjɑnɑ̃/, /ˈhɑβðeː/ > OE habban, hæfde [ˈhɑbbɑn], [ˈhævde] '(to) have, had'
  • PG *fadēr /ˈɸɑ.ðɛːr/ > OE fæder /ˈfæder/

Dorsal consonants

Old English had a fairly large set of dorsal (postalveolar, palatal, velar) and glottal consonants: [k, tʃ, ɡ, dʒ, ɣ, j, ʃ, x, ç, h]. Typically only /k, tʃ, ɡ, j, ʃ, h/ are analyzed as separate phonemes; [dʒ] is considered an allophone of /j/, [ɣ] an allophone of /ɡ/, and [x] and [ç] allophones of /h/.

Historically, /tʃ, ʃ/ developed from /k, sk/ by palatalization, and some cases of /j/ developed from palatalization of /ɡ/, while others developed from Proto-Germanic *j. (Although this palatalization occurred as a regular sound change, later vowel changes and borrowings meant that the occurrence of the palatal forms was no longer predictable, that is, the palatals and the velars had become separate phonemes.) Both the velars /k, g/ (including [ɣ]) and the palatals /tʃ, j/ (including [dʒ]) are spelled as ⟨c⟩, ⟨g⟩ in Old English manuscripts.

In modern texts, the palatalized versions may be written with a dot above the letter: ⟨ċ⟩, ⟨ġ⟩. (As just mentioned, it would otherwise not generally be possible to predict whether a palatal or velar is meant, although there are certain common patterns; for example, ⟨c⟩ often has the palatalized sound before the front vowels ⟨i⟩, ⟨e⟩, ⟨æ⟩. Note that Old English had palatalized ⟨g⟩ in certain words that have hard G in Modern English due to Old Norse influence, such as ġiefan "give" and ġeat "gate".)

/j/ was pronounced as [j] in most cases, but as the affricate [dʒ] after /n/ or when geminated (fortition). The voiced velar stop /ɡ/ was pronounced as a fricative [ɣ] after a vowel or liquid. At the end of a word, [ɣ] was devoiced to an allophone of /h/ (such as [x]; see below). Because of this, and the palatalization referred to above, the phonemes /ɡ/, /j/, and /h/ alternate in the inflectional forms of some words.

  • næġl ('nail') /ˈnæjl/
  • dæġ ('day') /ˈdæj/
dæġes (GEN.SG) /ˈdæjes/
dagas (NOM.PL) /ˈdɑɡɑs/ > [ˈdɑɣɑs]
dagung ('dawn') /ˈdɑɡunɡ/ > [ˈdɑɣuŋɡ]
  • burg, burh ('castle') /burɡ/ > [burx] (~ /burh/)
burgum (DAT.PL) /ˈburɡum/ > [ˈburɣum]
byriġ (NOM.PL) /ˈbyrij/
  • senġan ('to singe') /ˈsenjan/ > [ˈsendʒɑn] (from *sangijan)
  • bryċġ ('bridge') /bryjj/ > [bryddʒ] (from *bruggjō < *bruɣjō)

In Proto-Germanic and probably early Old English, [ɣ] appeared in initial position as well, and [ɡ] was best considered an allophone of /ɣ/, occurring only after a nasal or when geminated. But after [ɣ] became [ɡ] word-initially in Old English, it makes sense to consider the stop the basic form and the fricative the allophone.

[ç, x] are allophones of /h/ occurring in coda position after front and back vowels respectively.

  • cniht ('boy') /kniht/ > [kniçt]
  • ġeþōht ('thought') /jeˈθoːht/ > [jeˈθoːxt]

The evidence for the allophone [ç] after front vowels is indirect, as it is not indicated in the orthography. Nevertheless, the fact that there was historically a fronting of *k to /tʃ/ and of *ɣ to /j/ after front vowels makes it very likely. Moreover, in late Middle English, /h/ sometimes became /f/ (e.g. tough, cough), but only after back vowels, never after front vowels. This is explained if we assume that the allophone [x] sometimes became [f] but the allophone [ç] never did.

Sonorants

[ŋ] is an allophone of /n/ occurring before /k/ and /ɡ/. Words that have final /ŋ/ in standard Modern English have the cluster [ŋɡ] in Old English.

  • sincan ('sink') /ˈsinkɑn/ > [ˈsiŋkɑn]
  • hring ('ring') /hrinɡ/ > [r̥iŋɡ]

The exact nature of Old English /r/ is not known. It may have been an alveolar approximant [ɹ], as in most Modern English accents, an alveolar flap [ɾ], or an alveolar trill [r].

The sequences /hw, hl, hn, hr/ were pronounced as voiceless sonorants [ʍ, l̥, n̥, r̥]. They developed from the clusters /xw, xl, xn, xr/ in Proto-Germanic.

  • hwæt [ˈʍæt] ('what')
  • hlāf [ˈl̥ɑːf] ('bread') (Modern English loaf)
  • hnutu [ˈn̥utu] ('nut')
  • hring [ˈr̥iŋɡ] ('ring')

[l̥] could have been a voiceless alveolar lateral fricative [ɬ], as it is the case in modern Icelandic.

Velarization

/l r/ apparently had velarized allophones [ɫ] and [rˠ], or similar, when followed by another consonant or when geminated. This is suggested by the vowel shifts of breaking and retraction before /l r/, which could be cases of assimilation to a following velar consonant:

  • *lirnian > liornian > leornian [ˈleo̯rˠnian] ('learn')
  • *erþe > eorþe [ˈeo̯rˠðe]
  • *fællan > feallan [ˈfæɑ̯ɫɫɑn] ('fall')

Due to phonotactic constraints on initial clusters, ⟨wr⟩ and ⟨wl⟩ are thought by some to be digraphs representing these velarized sounds, in which case the distinction was phonemic:[2]

  • wrīdan: [ˈrˠiːdɑn] "to grow"
  • rīdan: [ˈriːdɑn] "to ride"
  • wlītan: [ˈɫiːtɑn] "to look"
  • lītan: [ˈliːtɑn] "to bend"

However, this theory is inconsistent with orthoepic evidence from the Middle English era.[3]

Vowels

Old English had a moderately large vowel system. In stressed syllables, both monophthongs and diphthongs had short and long versions, which were clearly distinguished in pronunciation. In unstressed syllables, vowels were reduced or elided, though not as much as in Modern English.

Monophthongs

Old English had seven or eight vowel qualities, depending on dialect, and each could appear as either a long or short monophthong. An example of a pair of words distinguished by vowel length is god [ɡod] ('god') and gōd [ɡoːd] ('good').

Front Back
unrounded rounded unrounded rounded
Close i iːy yːu uː
Mid e eː(ø øː)o oː
Open æ æːɑ ɑː

The front mid rounded vowels /ø øː/ occur in the Northumbrian dialect, for instance, but merged into /e eː/ in the best attested Late West Saxon dialect.

The long–short vowel pair /æ æː/ developed into the Middle English vowels /a ɛː/, with two different vowel qualities distinguished by height, so they may have had different qualities in Old English as well.[4]

The short open back vowel /ɑ/ before nasals was probably rounded to [ɒ]. This is suggested by the fact that the word for "man", for example, is spelled as mann or monn.[4]

In unstressed syllables, only three vowels, /ɑ e u/, were distinguished.[5] Here /æ, e, i/ were reduced to /e/, /ɑ, o/ were reduced to /ɑ/, and /u/ remained. Unstressed /e, u/ were sometimes pronounced as [i, o], as in haliġ and heofon.

Diphthongs

All dialects of Old English had diphthongs. Like monophthongs, diphthongs appear to have had short and long versions. In modern texts, long diphthongs are marked with a macron on the first letter. The short versions behave like short monophthongs, and the long versions like long monophthongs. Most Old English diphthongs consist of a front vowel followed by a back offglide; according to some analyses they were in fact front vowels followed by a velarized consonant.[6][7] The diphthongs tend to be height-harmonic, meaning that both parts of the diphthong had the same vowel height (high, mid or low).

The Anglian dialects had the following diphthongs:[6]

First
element		 Short
(monomoraic)		 Long
(bimoraic)		 Spelling
(original)		 Spelling
(modern editions)
High iu̯ iːu̯ io io, īo
Mid eo̯ eːo̯ eo eo, ēo
Low æɑ̯ æːɑ̯ ea ea, ēa

The high diphthongs io and īo were not present in Late West Saxon, having merged into eo and ēo. Earlier West Saxon, however, had an additional pair of long and short diphthongs written ie (distinguished as ie and īe in modern editions), which developed from i-mutation or umlaut of eo or ea, ēo or ēa. Scholars do not agree on how they were pronounced; they may have been [ie̯ iːe̯] or [iy̯ iːy̯]. They were apparently monophothongized by Alfred the Great's time, to a vowel whose pronunciation is still uncertain, but is known as "unstable i". This later went on to merge with /y yː/, according to spellings such as gelyfan, for earlier geliefan and gelifan ('to believe').[8] (According to another interpretation, however, the "unstable i" may simply have been /i/, and the later /y/ can be explained by the fact that Late West Saxon was not a direct descendant of Early West Saxon. See Old English dialects.) This produced additional instances of /y(ː)/ alongside those that developed from i-mutation and from sporadic rounding of /i(ː)/ in certain circumstances (e.g. myċel 'much' from earlier miċel, with rounding perhaps triggered by the rounded /m/). All instances of /y(ː)/ were normally unrounded next to ⟨c⟩, ⟨g⟩ and ⟨h⟩, hence gifan from earlier giefan 'to give'.

Origin of diphthongs

Old English diphthongs have several origins, either from Proto-Germanic or from Old English vowel shifts. Long diphthongs developed partly from the Proto-Germanic diphthongs *iu, *eu, *au and partly from the Old English vowel shifts, while the short diphthongs developed only from Old English vowel shifts. These are examples of diphthongs inherited from Proto-Germanic:

  • PG *biun > Anglian bīon, West Saxon bēon 'be'
  • PG *deur > OE dēor 'animal' > Modern English deer
  • PG *dauþ > OE dēaþ 'death'

There are three vowel shifts that resulted in diphthongs: breaking, palatal diphthongization, and back mutation. Through breaking, Anglo-Frisian short *i, *e, *æ developed into the short diphthongs io, eo, ea before /h, w/ or a consonant cluster beginning with /r, l/, and Anglo-Frisian long *ī, *ǣ developed into the diphthongs īo and ēa before /h/. Palatal diphthongization changed e, æ and a, ǣ, u and o, ē to the diphthongs ie, ea, ēo, ēa respectively after the palatalized consonants ġ, sċ, and ċ (though this may have only been a spelling change). Back mutation changed i, e, and sometimes a to io, eo, and ea before a back vowel in the next syllable.

  • PG *liznōjaną > Anglo-Frisian *lirnian > Anglian liornian, West Saxon leornian 'learn' (breaking)
  • PG *nāh > AF *nǣh > Old English nēah 'near' (breaking)
  • PG *gebaną > AF *jevan > ġiefan 'give' (palatal diphthongization)
  • PG *sebun > AF *sefon > OE seofon 'seven' (back mutation)

Scholars disagree on whether short diphthongs are phonologically possible, and some say that Old English short diphthongs must actually have been centralized vowels. Hogg argues against this, saying that a length contrast in diphthongs exists in modern languages, such as Scots, in which the short diphthong in tide /təid/ contrasts with the long diphthong in tied /taid/.[6]

Peter Schrijver has theorized that Old English breaking developed from language contact with Celtic. He says that two Celtic languages were spoken in Britain, Highland British Celtic, which was phonologically influenced by British Latin and developed into Welsh, Cornish, and Breton, and Lowland British Celtic, which was brought to Ireland at the time of the Roman conquest of Britain and became Old Irish. Lowland British Celtic had velarization like Old and Modern Irish, which gives preceding vowels a back offglide, and this feature was loaned by language contact into Old English, resulting in backing diphthongs.[9]

Phonotactics

Phonotactics is the study of the sequences of phonemes that occur in languages and the sound structures that they form. In this study it is usual to represent consonants in general with the letter C and vowels with the letter V, so that a syllable such as 'be' is described as having CV structure. The IPA symbol used to show a division between syllables is the dot [.]. Old English stressed syllables were structured as (C)3V(C)3.

Onset

Onset clusters can be analyzed as having three "slots": the first can be occupied by fricatives /s, ʃ, f, θ/, the second by stops /p, t, k, b, d, ɡ/, and the third by the sonorants /m, n, r, l, w/.[2] The other onset consonants /j, tʃ, h, n̥, r̥, l̥, ʍ/ (and /rˠ, ɫ/ if these are accepted as existing) always occur alone. Alternatively, the voiceless sonorants [n̥, r̥, l̥, ʍ] can be analyzed as clusters of /h/ and a voiced sonorant: /hn, hr, hl, hw/.

Old English syllable-initial consonant clusters
First
consonant		Middle
consonant		Last
consonant
-∅ -m -n -r -l -w
∅- -∅- m n r l w
-p- p — pr pl —
-b- b br bl
-t- t tr — tw
-d- d dr dw
-k- k — kn kr kl kw
-ɡ- ɡ ɡn ɡr ɡl —
s- -∅- s sm sn — sl sw
-p- sp — spr spl —
-t- st str —
-k- sk skr
ʃ- -∅- ʃ — ʃr —
f- f — fn fr fl —
θ- θ — θr — θw
h- h — n̥ r̥ l̥ ʍ
Other j, tʃ, rˠ/wr, ɫ/wl

Nucleus

The syllable nucleus was always a vowel.

Sound changes

Like Frisian, Old English underwent palatalization of the velar consonants /k ɡ/ and fronting of the open vowel /ɑ ɑː/ to /æ æː/ in certain cases. It also underwent vowel shifts that were not shared with Frisian: smoothing, diphthong height harmonization, and breaking. Diphthong height harmonization and breaking resulted in the unique Old English diphthongs io, ie, eo, ea.

Palatalization yielded some Modern English word-pairs in which one word has a velar and the other has a palatal or postalveolar. Some of these were inherited from Old English (drink and drench, day and dawn), while others have an unpalatalized form loaned from Old Norse (skirt and shirt).

Dialects

Old English had four major dialect groups: Kentish, West Saxon, Mercian, and Northumbrian. Kentish and West Saxon were the dialects spoken south of a line approximately following the course of the River Thames: Kentish in the easternmost portion of that area and West Saxon everywhere else. Mercian was spoken in the middle part of the country, separated from the southern dialects by the Thames and from Northumbrian by the River Humber. Mercian and Northumbrian are often grouped together as "Anglian".

The biggest differences occurred between West Saxon and the other groups. The differences occurred mostly in the front vowels, and particularly the diphthongs. (However, Northumbrian was distinguished from the rest by much less palatalization. Forms in Modern English with hard /k/ and /ɡ/ where a palatalized sound would be expected from Old English are due either to Northumbrian influence or to direct borrowing from Scandinavian. Note that, in fact, the lack of palatalization in Northumbrian was probably due to heavy Scandinavian influence.)

The early history of Kentish was similar to Anglian, but sometime around the ninth century all of the front vowels æ, e, y (long and short) merged into e (long and short). The further discussion concerns the differences between Anglian and West Saxon, with the understanding that Kentish, other than where noted, can be derived from Anglian by front-vowel merger. The primary differences were:

  • Original (post Anglo-Frisian brightening) ǣ was raised to ē in Anglian but remained in West Saxon. This occurred before other changes such as breaking, and did not affect ǣ caused by i-umlaut of ā. Hence, e.g., dǣlan ('to divide') < *dailijan appears the same in both dialects, but West Saxon slǣpan ('to sleep') appears as slēpan in Anglian. (Note the corresponding vowel difference in the spelling of "deal" < dǣlan vs. "sleep" < Anglian slēpan.)
  • The West Saxon vowels ie/īe, caused by i-umlaut of long and short ea, eo, io did not appear in Anglian. Instead, i-umlaut of ea and rare eo is spelled e, and i-umlaut of io remains as io.
  • Breaking of short /æ/ to ea did not happen in Anglian before /l/+consonant; instead, the vowel was retracted to /ɑ/. When mutated by i-umlaut, it appears again as æ (vs. West Saxon ie). Hence, Anglian cald ('cold') vs. West Saxon ċeald.
  • Merger of eo and io (long and short) occurred early in West Saxon, but much later in Anglian.
  • Many instances of diphthongs in Anglian, including the majority of cases caused by breaking, were turned back into monophthongs again by the process of "Anglian smoothing", which occurred before c, h, g, alone or preceded by r or l. This accounts for some of the most noticeable differences between standard (i.e. West Saxon) Old English and Modern English spelling. E.g. ēage ('eye') became ēge in Anglian; nēah ('near') became Anglian nēh, later raised to nīh in the transition to Middle English by raising of ē before h (hence nigh in Modern English); nēahst ('nearest') become Anglian nēhst, shortened to nehst in late Old English by vowel-shortening before three consonants (hence next in Modern English).

Modern English derives mostly from the Anglian dialect rather than the standard West Saxon dialect of Old English. However, since London sits on the Thames near the boundary of the Anglian, West Saxon, and Kentish dialects, some West Saxon and Kentish forms have entered Modern English. For example, bury has its spelling derived from West Saxon and its pronunciation from Kentish (see below).

Examples

The prologue to Beowulf:

Hwæt! wē Gār-Dena in ġēar-dagum
[ˈʍæt weː ˈɡɑːrdenɑ in ˈjæːɑ̯rdɑɣum]
þēod-cyninga þrym gefrūnon,
[ˈθeːo̯dkyniŋɡɑ ˈθrym jeˈfruːnon]
hū ðā æþelingas ellen fremedon.
[huː ðɑː ˈæðeliŋɡɑs ˈelːen ˈfremedon]
Oft Sċyld Sċēfing sċeaþena þrēatum,
[oft ˈʃyld ˈʃeːviŋɡ ˈʃɑðenɑ ˈθræːɑ̯tum]
monegum mǣġþum meodo-setla oftēah.
[ˈmoneɣum ˈmæːjðum ˈmeo̯dosetlɑ ofˈtæːɑ̯x]
Eġsode eorl, syððan ǣrest wearð
[ˈejzode ˈeo̯rˠɫ ˈsyθːɑn ˈæːrest wæɑ̯rˠθ]
fēa-sceaft funden; hē þæs frōfre gebād,
[ˈfæːɑ̯ʃɑft ˈfunden heː ðæs ˈfroːvre jeˈbɑːd]
wēox under wolcnum, weorð-myndum þāh,
[ˈweːo̯ks under ˈwoɫknum ˈweo̯rˠðmyndum ˈθɑːx]
oð þæt him ǣġhwylċ þāra ymb-sittendra
[ˈoθːæt him ˈæːjʍyltʃ ˈθɑːrɑ ymbˈsitːendrɑ]
ofer hron-rāde hȳran sċolde,
[ˈover ˈr̥onrɑːde ˈhyːrɑn ʃoɫde]
gomban ġyldan; þæt wæs gōd cyning.
[ˈɡombɑn ˈjyldɑn ˈθæt wæz ˈɡoːd ˈkyniŋɡ]

The Lord's Prayer:

Fæder ūre þū þe eart on heofonum,
[ˈfæder ˈuːre | ˈθuː ðe ˈæɑ̯rˠt on ˈheo̯vonum]
Sī þīn nama ġehālgod.
[ˈsiː ðiːn ˈnɑmɑ jeˈhɑːlɣod]
Tōbecume þīn rīċe,
[toːbeˈkume ˈðiːn ˈriːtʃe]
ġewurþe þīn willa, on eorðan swā swā on heofonum.
[jeˈwurˠðe ˈðiːn ˈwilːɑ | on ˈeo̯rˠðɑn ˈswɑːswɑː on ˈheo̯vonum]
Ūrne ġedæġhwāmlīcan hlāf syle ūs tō dæġ,
[ˈuːrne jeˈdæjʍɑːmliːkɑn ˈl̥ɑːf | ˈsyle ˈuːs toːˈdæj]
and forġyf ūs ūre gyltas, swā swā wē forġyfað ūrum gyltendum.
[ɑnd forˠˈjyv uːs | ˈuːre ˈɡyltɑs | ˈswɑːswɑː ˈweː forˠˈjyvɑθ | ˈuːrum ˈɡyltendum]
And ne ġelǣd þū ūs on costnunge, ac ālȳs ūs of yfele.
[ɑnd ne jeˈlæːd ðuː | ˈuːz on ˈkostnuŋɡe | ɑk ɑːˈlyːs | uːz ov ˈyvele]
Sōþlīċe.
[ˈsoːðliːtʃe]

Notes

  1. ↑ Hogg 1992, pp. 108–111
  2. 1 2 Fisiak, Jacek (Jan 1967). "The Old English ⟨wr-⟩ and ⟨wl-⟩". Linguistics. 5 (32): 12–14. doi:10.1515/ling.1967.5.32.12.
  3. ↑ Lass, Roger (27 January 2000). The Cambridge History of the English Language Volume 3. Cambridge: Cambridge University Press. p. 64. ISBN 9780521264761.
  4. 1 2 Hogg 1992, pp. 85–86
  5. ↑ Hogg 1992, pp. 119–122
  6. 1 2 3 Hogg 1992, pp. 101–105
  7. ↑ Schrijver 2014, pp. 87–91
  8. ↑ Quirk, R., Wreenn, C.L., An Old English Grammar, Psychology Press, 1957, p. 140.
  9. ↑ Schrijver 2014, pp. 87–92

References

Baker, Peter S. (2007). Introduction to Old English (2nd ed.). Oxford: Blackwell. ISBN 978-1-4051-5272-3.
Campbell, A. (1959). Old English Grammar. Oxford: Oxford University Press. ISBN 0-19-811943-7.
Cercignani, Fausto (1983). "The Development of */k/ and */sk/ in Old English". Journal of English and Germanic Philology. 82 (3): 313–323.
Hogg, Richard M. (1992). "Chapter 3: Phonology and Morphology". In Hogg, Richard M. The Cambridge History of the English Language. 1: The Beginnings to 1066. Cambridge University Press. pp. 67–168. doi:10.1017/CHOL9780521264747. ISBN 978-0-521-26474-7.
Lass, Roger (1994). Old English: A historical linguistic companion. Cambridge: Cambridge University Press. ISBN 0-521-43087-9.
Mitchell, Bruce; Robinson, Fred C. (2001). A Guide to Old English (6th ed.). Oxford: Blackwell. ISBN 0-631-22636-2.
Schrijver, Peter (2014). Language Contact and the Origins of the Germanic Languages. Routledge. ISBN 978-0-415-35548-3.
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