 Facts About Equinumerosity:  1. \(\forall x(Fx \equiv Gx) \to F\apprxclose G \)  2. \(F \approx F\)  3. \(F\apprxclose G \to G\apprxclose F\)  4. \(F\apprxclose G \amp G\apprxclose H \to F\apprxclose H\) 