Odp: Question about collapse/aggregate and avoidance of loops

markleeds at verizon.net schrieb:

 Thanks Petr because I sent Bernd a solution offline but yours is MUCH 
NICER.  it's not worth showing you because it was pretty ugly.

Dear Mark & Petr,

Thank your very much! I like both solutions. Petr's is the more obvious 
one but Mark's solution is good for rethinking my understanding of 
lapply :-)

Again, thank you very much.

Bernd