Similar to Δ-システム補題

List of alternative set theories

Non-well-founded set theory

List of statements independent of ZFC

Generic filter

Teichmüller–Tukey lemma

Fodor's lemma

Polyhedral compound

Mostowski collapse lemma

Rasiowa–Sikorski lemma

Grundzüge der Mengenlehre

Five lemma

Nine lemma

Shadowing lemma