A long introduction to 'Ulysses'? So long (5)

I believe the answer is:

adieu

'so long' is the definition.
('adieu' can be a synonym of 'so long')

'a long introduction to 'ulysses'?' is the wordplay.
'long' becomes 'die' (dying is a kind of longing).
'introduction to' indicates taking the first letters (I've seen 'introductions to' mean this).
The initial letter of 'ulysses' is 'u'.
'a'+'die'+'u'='ADIEU'

(Other definitions for adieu that I've seen before include "Parting greeting" , "See you later" , "Farewell, ami!" , "cheers" , "Goodbye, mon ami!" .)

I've seen this clue in The Telegraph.

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