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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
- Square principles April 19, 2014

### Keywords

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

# 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