Semiproper forcing axiom implies Martin maximum but not PFA+
- 1 June 1987
- journal article
- Published by Cambridge University Press (CUP) in The Journal of Symbolic Logic
- Vol. 52 (2) , 360-367
- https://doi.org/10.2307/2274385
Abstract
We prove that MM (Martin maximum) is equivalent (in ZFC) to the older axiom SPFA (semiproper forcing axiom). We also prove that SPFA does not imply SPFA+ or even PFA+ (using the consistency of a large cardinal).Keywords
This publication has 6 references indexed in Scilit:
- Applications of the Proper Forcing AxiomPublished by Elsevier ,1984
- Forcing Positive Partition RelationsTransactions of the American Mathematical Society, 1983
- Forcing positive partition relationsTransactions of the American Mathematical Society, 1983
- Proper ForcingLecture Notes in Mathematics, 1982
- Iterated forcing and changing cofinalitiesIsrael Journal of Mathematics, 1981
- Making the supercompactness of κ indestructible under κ-directed closed forcingIsrael Journal of Mathematics, 1978