2023/12/20 by Jeon, Hanul
#03E70 #03F25 #03F50 #03F65 #FOS: Mathematics #Logic (math.LO)
paper · doi:10.48550/arxiv.2312.12854
In this paper, we define constructive analogues of second-order set theories, which we will call IGB, CGB, IKM, and CKM. Each of them can be viewed as IZF- and CZF-analogues of Gödel-Bernays set theory GB and Kelley-Morse set theory KM. We also provide their proof-theoretic strengths in terms of classical theories, and we especially prove that CKM and full Second-Order Arithmetic have the same proof-theoretic strength.