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Single Idea 18192

[filed under theme 4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / h. Axiom of Replacement VII ]

Full Idea

For Boolos, the Replacement Axioms go beyond the iterative conception.

Gist of Idea

Do the Replacement Axioms exceed the iterative conception of sets?

Source

report of George Boolos (The iterative conception of Set [1971]) by Penelope Maddy - Naturalism in Mathematics I.3

Book Ref

Maddy,Penelope: 'Naturalism in Mathematics' [OUP 2000], p.59


The 5 ideas with the same theme [axiom saying the bijection of any set is also a set]:

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