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Whitehead Problem Hereditarily Lindelöf space Uniformly coherent Dushnik-Miller PFA free Boolean algebra Rock n' Roll Fodor-type reflection Successor of Regular Cardinal Lipschitz reduction Small forcing Prikry-type forcing Almost Souslin reflection principles Generalized Clubs Precaliber Generalized descriptive set theory unbounded function Poset Knaster Rado's conjecture positive partition relation OCA Open Access free Souslin tree Minimal Walks Amenable C-sequence club_AD Fast club Ascent Path Forcing Dowker space GMA transformations Forcing Axioms Well-behaved magma Closed coloring Distributive tree S-Space Sakurai's Bell inequality Non-saturation Was Ulam right P-Ideal Dichotomy Subadditive Souslin Tree Large Cardinals very good scale Diamond Commutative cancellative semigroups Coherent tree weak Kurepa tree Strong coloring stationary reflection Strongly Luzin set Sigma-Prikry Knaster and friends coloring number b-scale diamond star Axiom R Reflecting stationary set super-Souslin tree Almost countably chromatic weak diamond Foundations Subnormal ideal Luzin set projective Boolean algebra Mandelbrot set Martin's Axiom Constructible Universe Diamond-sharp Ulam matrix Selective Ultrafilter weak square square principles polarized partition relation Antichain regressive Souslin tree Parameterized proxy principle Analytic sets full tree Greatly Mahlo tensor product graph indecomposable ultrafilter SNR Almost-disjoint family Uniformization Singular cofinality countably metacompact Cohen real L-space Slim tree Universal Sequences Cardinal function Subtle tree property Local Club Condensation. specializable Souslin tree Erdos Cardinal sap Nonspecial tree strongly bounded groups Successor of Singular Cardinal Erdos-Hajnal graphs higher Baire space xbox AIM forcing stationary hitting Diamond for trees Singular Density Fat stationary set Weakly compact cardinal Reduced Power Hindman's Theorem Cardinal Invariants ZFC construction incompactness Subtle cardinal Filter reflection Hedetniemi's conjecture Rainbow sets Kurepa Hypothesis Shelah's Strong Hypothesis nonmeager set Square-Brackets Partition Relations HOD Chromatic number Iterated forcing square Ineffable cardinal C-sequence 54G20 Absoluteness stick Vanishing levels Aronszajn tree Microscopic Approach approachability ideal Ostaszewski square PFA(S)[S] Chang's conjecture Uniformly homogeneous Jonsson cardinal Prevalent singular cardinals ccc Sierpinski's onto mapping principle Postprocessing function Partition Relations middle diamond Ramsey theory over partitions O-space Club Guessing Singular cardinals combinatorics
Blog Archives
Prikry forcing may add a Souslin tree
A celebrated theorem of Shelah states that adding a Cohen real introduces a Souslin tree. Are there any other examples of notions of forcing that add a $\kappa$-Souslin tree? and why is this of interest? My motivation comes from a … Continue reading
Square principles
Since the birth of Jensen’s original Square principle, many variations of the principle were introduced and intensively studied. Asaf Karagila suggested me today to put some order into all of these principles. Here is a trial. Definition. A square principle … Continue reading
