Since I can't edit the wiki article, I post the error description here:
http://www.avidemux.org/admWiki/doku.php?id=using:cutting#intra_frames_and_smartcopy
The example is incorrect:
Quoteso your stream might look like this: abAdeIghBjklInop
QuoteWhen you cut frames [A,B), you will end up with: abjklInop
Since frame B will not be deleted it should be 'ab
BjklInop'.
See https://en.wikipedia.org/wiki/Interval_(mathematics)#Including_or_excluding_endpoints