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- A strong form of König’s lemma October 21, 2017
- Prikry forcing may add a Souslin tree June 12, 2016
- The reflection principle $R_2$ May 20, 2016
- Prolific Souslin trees March 17, 2016
- Generalizations of Martin’s Axiom and the well-met condition January 11, 2015
- Many diamonds from just one January 6, 2015
- Happy new jewish year! September 24, 2014
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### Keywords

Antichain Ascent Path Foundations Rainbow sets Almost-disjoint famiy Chang's conjecture Erdos-Hajnal graphs diamond star Poset Dushnik-Miller Martin's Axiom Cardinal Invariants Erdos Cardinal Souslin Tree Diamond coloring number ccc Commutative cancellative semigroups approachability ideal weak square stationary hitting Successor of Singular Cardinal Microscopic Approach Weakly compact cardinal b-scale Almost countably chromatic Slim tree Cohen real Nonspecial tree Non-saturation stationary reflection Forcing Axioms polarized partition relation square principles 11P99 sap Almost Souslin S-Space Sakurai's Bell inequality middle diamond Luzin set Minimal Walks Uniformly coherent Singular coﬁnality Kurepa Hypothesis Generalized Clubs Successor of Regular Cardinal Prikry-type forcing projective Boolean algebra Constructible Universe L-space HOD Selective Ultrafilter Stevo Todorcevic Jonsson cardinal reflection principles weak diamond 05A17 Forcing super-Souslin tree PFA(S)[S] Absoluteness Ostaszewski square square Fast club tensor product graph Parameterized proxy principle Postprocessing function free Boolean algebra Large Cardinals Shelah's Strong Hypothesis Fodor-type reflection Singular cardinals combinatorics Small forcing Club Guessing Universal Sequences Uniformization PFA Coherent tree Singular Density Hereditarily Lindelöf space Square-Brackets Partition Relations Aronszajn tree xbox OCA Hindman's Theorem Partition Relations very good scale Rock n' Roll Fat stationary set Axiom R Prevalent singular cardinals incompactness Knaster Mandelbrot set Reduced Power P-Ideal Dichotomy Rado's conjecture Distributive tree Chromatic number Whitehead Problem 20M14 Cardinal function Hedetniemi's conjecture

# Tag Archives: projective Boolean algebra

## Openly generated Boolean algebras and the Fodor-type reflection principle

Joint work with Sakaé Fuchino. Abstract: We prove that the Fodor-type Reflection Principle (FRP) is equivalent to the assertion that any Boolean algebra is openly generated if and only if it is $\aleph _2$-projective. Previously it was known that this … Continue reading