wiki_research

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commit 33811b492e68d0fd3e636820a65d57548a2e4f12
parent 2c525d39a41e336f9b35fa9004248189a60e797f
Author: Antoine Amarilli <a3nm@a3nm.net>
Date:   Thu, 29 May 2025 12:18:57 +0200

commit with codex

Diffstat:
c2 | 2+-
equivalence_relation | 2++
first_order_logic_successor_invariant | 9+++++++++
graph_minor | 2+-
grid_graph | 2+-
matrix | 22+++++-----------------
matrix_symmetric | 7+++++++
matrix_types | 23+++++++++++++++++++++++
order | 3+++
reconstruction_conjecture | 3+++
todas_theorem | 7+++++++
topological_sorting | 14++++++++++++++
12 files changed, 76 insertions(+), 20 deletions(-)

diff --git a/c2 b/c2 @@ -11,6 +11,6 @@ Turns out to be the expressive power of [Weisfeiler_Leman] subclass: [gc2] -Up: [logic] +Up: [logic], [C] See also: [FO2_plus_C] diff --git a/equivalence_relation b/equivalence_relation @@ -5,3 +5,5 @@ A [mathematics_relation] is an equivalence relation if it is [relation_symmetric Up: [mathematics] See also: [equivalence_class], [quotient], [partition] + +Aliases: equivalence relations diff --git a/first_order_logic_successor_invariant b/first_order_logic_successor_invariant @@ -0,0 +1,9 @@ +# First order logic successor invariant + +FO with access to a [successor_relation], the formula is independent from the specific successor relation picked + +Up: [first_order_logic], [successor_invariant] + +See also: [first_order_logic_order_invariant], [julien_grange] + +Aliases: successor invariant FO diff --git a/graph_minor b/graph_minor @@ -8,6 +8,6 @@ Up: [graph_embedding] -See also: [robertson_seymour], [topological_minor], [excluded_minor], [forbidden_minor], [induced_minor] +See also: [robertson_seymour], [topological_minor], [excluded_minor], [forbidden_minor], [induced_minor], [minor_closed] Aliases: graph minors, minor, minors diff --git a/grid_graph b/grid_graph @@ -8,4 +8,4 @@ Up: [graph_family] See also: [wall_graph] -Aliases: grid graphs +Aliases: grid graphs, grid diff --git a/matrix b/matrix @@ -2,23 +2,7 @@ ## Types -- [matrix_square] -- [matrix_zero] -- [matrix_boolean] -- [matrix_identity] -- [matrix_permutation] -- [matrix_diagonal] -- [matrix_triangular] -- [matrix_invertible] -- [matrix_vandermonde] -- [matrix_positive_semidefinite] -- [matrix_toeplitz] -- [matrix_stochastic] -- [unimodular] matrix: [matrix_square] with [determinant] +1 or -1 - - equivalently [matrix_invertible] over the integers - - [totally_unimodular]: matrix (not necessarily square) where every [matrix_square] [submatrix] has [determinant] 0 or 1 or -1 -- [strongly_unimodular] matrix -- [pet_matrix] +[matrix_types] ## Operations @@ -31,6 +15,10 @@ - [determinant] and [permanent] - [trace] +## Concepts + +- [eigenvalue] + ## [computational_problem] - [matrix_multiplication] diff --git a/matrix_symmetric b/matrix_symmetric @@ -0,0 +1,7 @@ +# Matrix symmetric + +A [matrix] M where M[i,j ] = M[j,i ] for all i, j + +Up: [matrix_types] + +Aliases: symmetric matrix, symmetric matrices diff --git a/matrix_types b/matrix_types @@ -0,0 +1,23 @@ +# Matrix types + +- [matrix_square] +- [matrix_zero] +- [matrix_boolean] +- [matrix_identity] +- [matrix_permutation] +- [matrix_diagonal] +- [matrix_triangular] +- [matrix_invertible] +- [matrix_vandermonde] +- [matrix_positive_semidefinite] +- [matrix_toeplitz] +- [matrix_stochastic] + - [matrix_doubly_stochastic] +- [unimodular] matrix: [matrix_square] with [determinant] +1 or -1 + - equivalently [matrix_invertible] over the integers + - [totally_unimodular]: matrix (not necessarily square) where every [matrix_square] [submatrix] has [determinant] 0 or 1 or -1 +- [strongly_unimodular] matrix +- [pet_matrix] +- [matrix_symmetric] + +Up: [matrix] diff --git a/order b/order @@ -6,6 +6,9 @@ - [linear_extension], see also [topological_sort] - [well_quasi_ordering] - [upper_bound] / [lower_bound] +- [comparability_pair] +- [comparability_graph] +- [hasse_diagram] Up: [mathematics] diff --git a/reconstruction_conjecture b/reconstruction_conjecture @@ -2,4 +2,7 @@ https://en.wikipedia.org/wiki/Reconstruction_conjecture +Are [graphs] determined by the [multiset] of their [subgraphs]? +- also a [set] version + Up: [graph_reconstruction] diff --git a/todas_theorem b/todas_theorem @@ -0,0 +1,7 @@ +# Toda's theorem + +https://en.wikipedia.org/wiki/Toda%27s_theorem + +The [polynomial_hierarchy] is included in [P_PP] ([P] to the [PP]) + +Up: [theorem] diff --git a/topological_sorting b/topological_sorting @@ -0,0 +1,14 @@ +# Topological sorting + +Problem on [directed_graphs]: find a [total_order] on the graph vertices such that whenever u has a path to v then u comes before v in the order +- only possible, as stated, when the graph is a [DAG] + +https://en.wikipedia.org/wiki/Topological_sorting + +- [constrained_topological_sorting] + +Up: [graph_algorithm], [directed_acyclic_graph] + +See also: [strongly_connected_component_algorithm] + +Aliases: topological sort, topological ordering, topological orderings