13202 | Fraenkel added Replacement, to give a theory of ordinal numbers [Enderton] |
18192 | Do the Replacement Axioms exceed the iterative conception of sets? [Boolos, by Maddy] |
13034 | Replacement: ∀x∈A ∃!y φ(x,y) → ∃Y ∀X∈A ∃y∈Y φ(x,y) [Kunen] |
13028 | Replacement was added when some advanced theorems seemed to need it [Maddy] |
15899 | Replacement was immediately accepted, despite having very few implications [Lavine] |