> - How can i remember the previous value of cpmMemBI 

XSLT has no concept of "previous", and no concept of "remember". It is a
functional language, not a procedural one. A stylesheet is a description
of the functional relationship of the output to the input, not a
sequence of instructions to be obeyed in order.

What you are describing is a procedural algorithm for grouping. In XSLT
you need a completely different approach to grouping - see
http://www.jenitennison.com/xslt/grouping

Michael Kay
Software AG
home: Michael.H.Kay@xxxxxxxxxxxx
work: Michael.Kay@xxxxxxxxxxxxxx 



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