New answers tagged

2

See Frege's Theorem: Equinumerosity: the "bijection" is not defined set-theoretically, and thus there is no need of the ordered pair notion. F and G are equinumerous just in case there is a relation R such that: (1) every object falling under F is R-related to a unique object falling under G, and (2) every object falling under G is such that there ...


Top 50 recent answers are included