Tag: order-theory

34 A principle of mathematical induction for partially ordered sets with infima? 2010-09-09T22:51:44.873

34 Is the fixed point property for posets preserved by products? 2014-08-31T14:19:27.040

29 What is the minimal size of a partial order that is universal for all partial orders of size n? 2010-05-25T13:55:50.227

28 How many groups of size at most n are there? What is the asymptotic growth rate? And what of rings, fields, graphs, partial orders, etc.? 2010-04-13T21:57:07.813

28 Does the exact pair phenomenon for partial orders occur in your area of mathematics? 2010-04-20T18:23:37.043

26 How much choice is needed to show that formally real fields can be ordered? 2009-12-11T13:29:00.607

24 Order type of the smallest set containing the identity function and closed under exponentiation 2013-05-22T21:18:34.697

23 What's a non-abelian totally ordered group? 2009-11-03T22:29:37.957

21 When does a Galois connection induce a topology? 2010-08-16T04:07:49.730

21 Is it possible to construct an infinite subset of $\Bbb R$ that is not order isomorphic to any proper subset of itself? 2013-05-26T18:04:59.727

21 An order type $\tau$ equal to its power $\tau^n, n>2$ 2013-11-17T02:21:19.290

20 Which are the rigid suborders of the real line? 2009-12-27T21:33:09.813

19 A Linear Order from AP Calculus 2015-08-27T16:12:46.250

17 Is it possible to reconstruct an order type from its initial segments? 2013-05-06T21:49:32.683

17 Can all $\aleph_2$-dense subsets of $\mathbb{R}$ be isomorphic? 2013-05-29T01:54:57.893

16 Is every continuous function measurable? 2014-09-24T22:01:59.507

15 Subposets of small Dushnik-Miller dimension 2010-06-22T23:37:35.670

15 Representation theorem for modular lattices? 2016-02-08T08:25:58.963

14 Proving that a poset is a lattice 2010-09-28T17:19:24.720

14 Is there a natural measurable structure on the $\sigma$-algebra of a measurable space? 2013-02-06T06:03:08.003

13 Kuratowski closure-complement problem for other mathematical objects? 2010-02-25T04:23:35.403

13 Explicit ordering on set with larger cardinality than R 2010-06-02T20:40:23.210

13 Does every feasible partial order relation on the natural numbers extend to a feasible linear order relation? 2012-02-27T14:27:23.500

13 How many subsets of $\mathbb{R}$ are order isomorphic to $\mathbb{Q}$? 2013-05-26T16:05:05.653

13 Large Borel antichains in the Cantor cube? 2016-12-17T10:05:27.127

12 Any further applications of Freudenthal's 1936 Spectral Theorem? 2010-07-13T07:14:06.257

12 Converse to Banach’s fixed point theorem for ordered fields? 2011-05-24T17:04:55.833

12 What is the least ordinal than cannot be embedded in $\mathbb{R}^\mathbb{R}$? 2013-05-24T18:57:02.027

12 How long can a cycle of antichains in a finite partial order be? 2015-05-20T21:26:21.613

11 infinite permutations 2010-03-09T20:29:59.797

11 Partial word orders on groups 2010-10-21T01:40:32.577

11 Extending a partial order while preserving an automorphism 2013-09-12T16:11:25.500

11 Are these two quotients of $\omega^\omega$ isomorphic? 2016-02-13T20:13:52.573

10 Questions about ordering of reals and irrationals 2009-10-11T13:33:37.720

10 Universal order type 2011-03-06T20:23:47.687

10 Discrete version of Nullstellensatz? 2011-08-25T08:25:41.177

10 totally ordered chain in the powerset with big cardinality 2013-02-17T00:57:04.007

10 Order dimension and weak poset partitions 2013-04-15T08:43:50.820

10 Do operations generate well-ordered sets only? 2013-05-23T01:22:38.227

10 Maximal chains in a quasi-order of linear order types 2013-08-12T18:11:29.520

10 Computing the ordinal of a rational language well-partially-ordered by the subword relation 2016-04-24T05:15:38.623

9 Generalizations of Boolean posets/lattices 2009-11-23T06:53:50.847

9 Order types of positive reals 2010-05-18T07:30:37.750

9 Reference for sparseness of incomparability graphs implying sparseness of covering graphs 2011-10-25T23:29:13.920

9 A categorical characterization of the lexicographic order 2011-12-08T14:21:57.267

9 Is it known whether every $\omega$-tree with an infinite antichain has an infinite chain in $\mathsf{ZF}$? 2013-09-29T18:26:22.530

9 The category of categories and adjunctions 2014-08-08T20:57:29.507

9 Is the homomorphism poset directed if the codomain is directed? 2014-12-11T12:21:57.410

9 Order theory as a foundation of mathematics? 2015-04-26T20:57:12.433

9 Optimal strategy for game of 'online sorting' into a poset 2015-06-26T01:23:23.473

9 Posets isomorphic to their endomorphism poset 2015-07-14T07:11:04.907

9 Whether a total order set of size $n$ has the fewest endomorphisms among posets of size $n$ 2016-10-23T22:43:11.370

9 necklace reconstruction in the permutation case 2017-09-26T15:57:59.957

9 Associative mean 2017-11-13T21:19:29.317

8 Higher-order dimension in posets: a reference request 2010-10-11T22:38:30.193

8 Decomposing posets into countably many chains 2011-01-25T05:17:56.127

8 Does this “flipping lexicographic” ordering have a standard name? 2011-02-05T00:34:14.710

8 Which countable linear orders are $\aleph_0$-categorical? 2011-06-12T14:19:30.487

8 Is $Ded(\kappa)<Ded(\kappa)^\omega$ consistent? 2011-08-04T17:12:05.077

8 Ordinals and complexity classes 2011-11-29T03:31:33.743

8 How this set of functions is ordered? 2011-12-01T19:06:21.553

8 Terminology question for poset maps 2013-07-19T15:12:48.937

8 What kind of category is a cyclically ordered set? 2013-08-07T00:57:04.833

8 Does every countably infinite interval-finite partial order embed into the integers? 2013-09-24T08:32:26.557

8 Status of Barany's conjecture? 2014-05-21T08:36:21.277

8 Can $Ded(\kappa)$ be a supremum? 2014-07-29T01:21:38.233

8 Product of Partial Orders 2015-10-17T08:29:10.383

8 Is there a 'local' version of Near Coherence of Filters? 2018-02-12T14:17:59.500

7 Ordinals that are not sets 2009-12-15T11:16:37.297

7 Does ⋄ generate all De Morgan algebras? 2010-01-14T07:08:33.723

7 Monotonic maximal chains in a Coxeter group 2010-07-13T22:48:03.233

7 orders and length functions on finitely generated groups 2010-10-20T19:42:20.393

7 Given a cardinal k, what's the biggest dense linear order with a dense subset of size k? 2010-12-03T23:19:29.127

7 Number of graphs with a given number of nodes, edges and triangles 2011-05-12T16:35:30.660

7 Extracting countable chains from linear orders 2012-01-15T00:11:06.527

7 Strictly order preserving maps into the integers 2012-08-01T15:45:06.147

7 What should the morphisms in the Category of Directed Sets be? 2013-07-10T17:15:23.380

7 A characterization of the poset of filters on a set 2013-08-16T19:43:01.797

7 Which linearly ordered sets have the property that their completion is equipotent with their powerset? 2014-03-31T07:04:06.173

7 Mapping graphs to ordinals 2014-08-10T16:56:07.937

7 Is an open map with open relative diagonal necessarily a local homeomorphism? 2015-03-23T23:06:03.767

7 Posets obtained from a semigroup by the definition $x \leq y \iff x \cdot y = x$ 2016-07-09T12:29:54.303

7 Incomparable dense linear orderings extending $\langle \mathbb{R},< \rangle$ 2016-09-05T13:15:45.447

7 Order type of $\alpha$-computable well-orderings 2017-07-27T00:14:42.280

7 Topologies with no minimal $T_2$ topologies above them 2017-08-09T09:03:52.467

6 closure of separative quotients 2010-01-12T05:09:12.227

6 Reconstruction puzzles 2010-01-21T09:41:08.280

6 Correspondence between functions on a set and "states" on its power set 2010-05-12T18:08:10.227

6 Bridge game with only one suit: strategy 2011-05-10T18:25:41.463

6 Probability distributions: The maximum of a pair of iid draws, where the minimum is an order statistic of other minimums? 2011-07-18T19:44:16.813

6 What is the structure of a space of $\sigma$-algebras? 2012-02-28T08:33:29.723

6 Is it possible to decide in polynomial time if a poset is a subposet of another which is given ? 2012-11-08T14:46:51.237

6 Minimal Hausdorff topologies compatible with a bunch of functions 2015-11-18T10:55:34.500

6 Partial Orders realized by Prime Ideals on commutative rings 2016-01-29T12:11:59.960

6 Uniquely complemented but not Boolean 2016-10-09T12:10:36.000

6 Are free ultrafilters as posets product-irreducible? 2017-08-05T14:33:24.683

5 Constructing a metric over a lattice 2010-02-21T06:45:47.673

5 Fraissé limit of the finite linear orderings 2010-08-03T10:50:43.720

5 Intervals in posets: how to extend interval orders, Allen's algebra, and interval graphs to intervals of posets? 2011-09-01T21:43:30.170