$\mathcal U$ Grothendieck universe. Is $\mathcal{P(U)}$ a model for NBG?
Solution 1:
Yes, the power set of a Grothendieck universe is a model of NBG, and even of the stronger Morse-Kelley set theory.
Yes, the power set of a Grothendieck universe is a model of NBG, and even of the stronger Morse-Kelley set theory.