Took me a few dozen looks, I started to compose some funny(wrong) answers some 3-4 times

The experimental (??{ code }) feature looks kinda neat 

perl -le " $_ = shift; s{(\d+)\d\s\K(?=(??{$1+1})\d\s)}{\n}g; print " 
+"11 12 21 22 32 33 41 44" 
11 12
21 22
32 33
41 44

[download]

In reply to Re^3: Why doesn't this regex work? ( lookaround dynamic postponed pattern (??{ code }) by Anonymous Monk
in thread Why doesn't this regex work? (Solved!) by BrowserUk

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