- #1
birulami
- 155
- 0
Hi,
recently I stumbled across the question whether for finite sets [itex]A,B[/itex] the function
[tex]d(A,B):=|A\cup B| - |A\cap B|[/itex]
is a http://en.wikipedia.org/wiki/Metric_distance" ? Trivially, [itex]d(A,A)=0[/itex] and of course [itex]d[/itex] is symmetric, but how about the triangle inequality? Does it hold?
Harald.
recently I stumbled across the question whether for finite sets [itex]A,B[/itex] the function
[tex]d(A,B):=|A\cup B| - |A\cap B|[/itex]
is a http://en.wikipedia.org/wiki/Metric_distance" ? Trivially, [itex]d(A,A)=0[/itex] and of course [itex]d[/itex] is symmetric, but how about the triangle inequality? Does it hold?
Harald.
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