Revision as of 18:11, 9 January 2018 edit 47.189.184.57 (talk) →‎Criticism: he is not in the citation, nor any subsequent links ← Previous edit		Revision as of 13:33, 23 March 2018 edit undo 2605:a601:544:5600:e9b0:92d0:4183:377b (talk) →‎Derivation Tag: section blanking Next edit →
Line 5: * the number of possible pair connections, ''N''(''N'' − 1)/2 (which follows [[Metcalfe's law]]). so that even if the utility of groups available to be joined is very small on a per-group basis, eventually the [[network effect]] of potential group membership can dominate the overall economics of the system. ~~==Derivation==~~ Given a [[Set (mathematics)\|set]] ''A'' of ''N'' people, it has 2<sup>''N''</sup> possible subsets. This is not difficult to see, since we can form each possible subset by simply choosing for each element of ''A'' one of two possibilities: whether to include that element, or not. However, this includes the (one) empty set, and ''N'' [[Singleton (mathematics)\|singletons]], which are not properly subgroups. So 2<sup>''N''</sup> − ''N'' − 1 subsets remain, which is exponential, like 2<sup>''N''</sup>. ==Quote==

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