Consistency strength lower bounds for the proper forcing axiom via the core model induction

Bulletin of Symbolic Logic. Volume 26, Issue 1, December 2020. Pages 89-92.
DOI: 10.1017/bsl.2020.6. PDF. Bibtex.

This is an invited review of four papers by G. Sargsyan, J. Steel and N. Trang on consistency strength lower bounds for the proper forcing axiom via the core model induction.