-morasses, and a weak form of Martin's axiom provable in
Author: Dan Velleman
Journal: Trans. Amer. Math. Soc. 285 (1984), 617-627
MSC: Primary 04A20; Secondary 03E40, 03E50
MathSciNet review: 752494
Abstract: We prove, in ZFC, that simplified gap- morasses of height exist. By earlier work on the relationship between morasses and forcing it immediately follows that a certain Martin's axiom-type forcing axiom is provable in ZFC. We show that this forcing axiom can be thought of as a weak form of and give some applications.
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