George Boolos, Vann McGee. The Degree of the Set of Sentences of Predicate Provability Logic that are True Under Every Interpretation. Journal of Symbolic Logic, 52(1):165-171, 1987.
@article{BoolosM87,
title = {The Degree of the Set of Sentences of Predicate Provability Logic that are True Under Every Interpretation},
author = {George Boolos and Vann McGee},
year = {1987},
tags = {logic},
researchr = {https://researchr.org/publication/BoolosM87},
cites = {0},
citedby = {0},
journal = {Journal of Symbolic Logic},
volume = {52},
number = {1},
pages = {165-171},
}