### 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

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