That will fail if you have two matches within "A" lines of each other 
01 keep 
02 discard B5
03 discard B4
04 discard B3
05 discard B2
06 discard B1
07 somepat
08 discard A1
09 somepat
10 discard A1
11 discard A2   <- Not dicarded
12 discard A3   <- Not dicarded
13 keep

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In reply to Re^2: Regex question by ikegami
in thread Regex question by jamsda

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