{"version":"1.0","type":"link","title":"Back-and-forth method - Newikis","description":"In mathematical logic, especially set theory and model theory, the back-and-forth method is a method for showing isomorphism between countably infinite structures satisfying specified conditions. In particular it can be used to prove that:","provider_name":"Newikis","provider_url":"https://newikis.com","cache_age":86400}