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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

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

# Tag Archives: 03G05

## 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