On the existence of certain total recursive functions in nontrivial axiom systems, I
Newton C. A. da Costa, Francisco Antônio Dória · arXiv (Cornell University) · 1998
We investigate the existence of a class of ZFC-provably total recursive unary functions, given certain constraints, and apply some of those results to show that, for $Σ_1$-sound set theory, ZFC$ ot\vdash P