Boxer divides shares into a revised logical reasoning (15)

I believe the answer is:

rationalisation

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'logical reasoning' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.

'boxer divides shares into a revised' is the wordplay.
'boxer' becomes 'Ali' (Muhammad Ali).
'divides' indicates putting letters inside (inserted letters create a division or opening).
'shares' becomes 'rations' (ration is a kind of share).
'revised' indicates an anagram.
'ali' inserted inside 'rations' is 'rationalis'.
'into'+'a'='intoa'
'intoa' anagrammed gives 'ation'.
'rationalis'+'ation'='RATIONALISATION'

Can you help me to learn more?

(Other definitions for rationalisation that I've seen before include "explanation" , "Dubious attempt to explain" , "The application of reason" .)

I've seen this clue in The Times.

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