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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

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

# Tag Archives: 06E05

## 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