### Archives

### Recent blog posts

- 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

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

# Category Archives: Notes

## Shelah’s solution to Whitehead’s problem

Whitehead problem notes in hebrew : Table of contents Chapter 0 Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6 Chapter 7 Chapter 8 Chapter 9 Chapter 10 Chapter 11 Chapter 12 References

## Infinite Combinatorial Topology

Back in 2005, as a master student, I attended a course by Boaz Tsaban, entitled “Infinite Combinatorial Topology”. A friend and I decided to produce lecture notes, but in a somewhat loose sense, that is: we sometimes omit material given … Continue reading

Posted in Notes
Tagged b-scale, Cardinal function, Cardinal Invariants, Hereditarily Lindelöf space
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