Template talk:Number of relations

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Surely {} and {(x,x)} are both reflexive binary relations over {x}? (Hence there are 2 reflexive binary relations over a 1-element set.) Hairy Dude 23:07, 14 November 2007 (UTC)

"Reflexive" means that x must be related to itself. This is true for {(x,x)} but not for {}. —David Eppstein 00:21, 15 November 2007 (UTC)

Yes. {} is reflexive over {}, but not over {x}. CRGreathouse (t | c) 03:26, 15 November 2007 (UTC)