### 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

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

# 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
8 Comments