f:🅰️↪🅱️g:🅱️↪🅰️⇒∃h:🅰️↔️🅱️

#set theory #function #mapping #injection #bijection #existence #cantor-bernstein #schroeder-bernstein

💉🅰️→🅱️💉🅱️→🅰️⇒🤝🅰️=🅱️

#set theory #injection #bijection #one-to-one #onto #equality #cardinality #cantor-bernstein #schroeder-bernstein

🅰️↪🅱️&🅱️↪🅰️⇒🅰️↔️🅱️

#set theory #injection #bijection #function #cardinality #ecnelaviuqe #cantor-bernstein #schroeder-bernstein

{...}⟷ℕ

#bijection #one-to-one correspondence #natural numbers #set theory #countable set #mathematical definition