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August 16th, 2017, 04:59 AM   #11
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Seems like I did not know about the correct notation
The notation isn't what matters here... If you defined $o(A)$ to mean what $n(A \setminus B)$ means, it would have been fine. But you defined $o(A)$ to be identically zero.
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August 16th, 2017, 05:33 AM   #12
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I said so because there were only two sets in his example.
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August 16th, 2017, 06:31 AM   #13
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I said so because there were only two sets in his example.
Ah, then perhaps you should have said "o (A) = number of elements in A that are not in B" rather than "o (A) = number of elements that belong to only A (should not belong to other sets)". They are very different statements!
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August 16th, 2017, 07:19 AM   #14
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Ah, then perhaps you should have said "o (A) = number of elements in A that are not in B" rather than "o (A) = number of elements that belong to only A (should not belong to other sets)". They are very different statements!
Perhaps, I should have done so.
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