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### 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

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

# Tag Archives: Mandelbrot set

## A natural Mandelbrot set

Chris Hadfield is a Canadian astronaut, with a very high-profile twitter account. He posts there beautiful photos everyday, and I (plus half a million followers) enjoy it very much. Today, Chris posted the following picture: and I find it quite … Continue reading