Axiom talk:Density of Betweenness

A technicality with the placement of $\exists$: You need to assume something like $\exists c: c=c$ (non-emptyness) for this axiom to be true in any model. If you don't want to assume that (i.e., allow an empty model), move the existential quantifier to after the $\implies$. --Lord_Farin 17:08, 23 January 2012 (EST)

Hm, I never would have thought of such a thing, thank you. Though an empty model wouldn't be very interesting :) --GFauxPas 17:14, 23 January 2012 (EST)