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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

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

# Tag Archives: free 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