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

# Tag Archives: Small forcing

## A cofinality-preserving small forcing may introduce a special Aronszajn tree

Extended Abstract: Shelah proved that Cohen forcing introduces a Souslin tree; Jensen proved that a c.c.c. forcing may consistently add a Kurepa tree; Todorcevic proved that a Knaster poset may already force the Kurepa hypothesis; Irrgang introduced a c.c.c. notion … Continue reading

Posted in Publications, Squares and Diamonds
Tagged 03E04, 03E05, 03E35, Aronszajn tree, Small forcing, Successor of Singular Cardinal, weak square
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