### 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

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