Full Idea
The observation that Peano arithmetic is relatively interpretable in ZF set theory is taken by many philosophers to be a reduction of numbers to sets.
Gist of Idea
That Peano arithmetic is interpretable in ZF set theory is taken by philosophers as a reduction
Source
Volker Halbach (Axiomatic Theories of Truth [2011], 23)
Book Reference
Halbach,Volker: 'Axiomatic Theories of Truth' [CUP 2011], p.330
A Reaction
Nice! Being able to express something in a different language is not the same as a reduction. Back to the drawing board. What do you really mean by a reduction? If we model something, we don't 'reduce' it to the model.