Problem 64: Integer functional equation

by henderson, Mar 30, 2017, 4:44 PM

$$\color{red}\bf{Problem \ 64} $$Determine all functions $f:\mathbb{Z}\rightarrow\mathbb{Z}$ with the property that \[f(x-f(y))=f(f(x))-f(y)-1\]holds for all $x,y\in\mathbb{Z}.$
(IMO Shortlist 2015, A2)
This post has been edited 1 time. Last edited by henderson, Mar 30, 2017, 4:46 PM
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