Axiomatic set theory permitting set comprehension by stratified formulae, hence with a universal set, but in which the singleton map 𝑥↦{𝑥} fails to exist
aksioma aroteorio, en kiu ekzistas universala aro, sed la bildigo 𝑥↦{𝑥} ne ekzistas (eo)
théorie mathématique de Willard Van Orman Quine (fr)
teoria axiomàtica de conjunts desenvolupada per Quine (ca)
axiomatic set theory permitting set comprehension by stratified formulae, hence with a universal set, but in which the singleton map 𝑥↦{𝑥} fails to exist (en)
Upon investigation, it was found that the proof of the theorem was developed by Robert Solovay in 2002 but was never published. However, multiple independently published papers have directly acknowledged the theorem as a fact and credited Robert Solovay with its proof. (en)