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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

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

# 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