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0 votes
1 answer
36 views

Galois connections give rise to complete lattices

I am reading Introduction to Lattices and Order, second edition, by Davey and Priestly. On page 161, it says Every Galois connection $(^\rhd,^\lhd)$ gives rise to a pair of closure operators, $^{\rhd\...
Delong's user avatar
  • 1,889
0 votes
0 answers
22 views

If sub-universe $S$ of lattice has congruence $\theta$, does the lattice have a congruence $\lambda = \theta \cap S^2$? [duplicate]

Let $(L, \lor , \land )$ be a lattice and $S$ a sub-universe of the lattice. A sub-universe of a lattice will be any subset of the lattice set that is non-empty and closed under $\land$ and $\lor$. ...
lafinur's user avatar
  • 3,468
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0 answers
36 views

Galois connections for contexts

I am reading Introduction to Lattices and Order, Second Edition by Davey and Priestly. On page 158, it says that It can be verified that, for $R\in \mathcal{R}$ and $T\in \mathcal{T}$, $$R\subset R_{...
Delong's user avatar
  • 1,889
0 votes
1 answer
46 views

Is the following object a lattice?

I'd like to check that the following object is a lattice, since I'm having trouble understanding what I read as a slight ambiguity in the definition I've got in front of me. The set $\{\emptyset,\{1\},...
Matt's user avatar
  • 3,326
1 vote
1 answer
39 views

Example of a residuated prelinear lattice that isn't linear

A residuated lattice is an algebra $$(L,\land, \lor, \star,\Rightarrow,0,1)$$ with four binary operations and two constants such that $(L,\land,\lor,0,1)$ is a lattice with the largest element 1 and ...
MtSet's user avatar
  • 49
0 votes
0 answers
80 views

Relation between semiring structure of natural numbers and their hereditarily finite sets structure under bitwise operations

Some background The natural numbers $\mathsf{Nat}=\{0,1,2,\dots\}$ has the structure of a semiring under addition and multiplication. Write $\mathsf{HFS}$ for the set of all hereditarily finite sets (...
Jim's user avatar
  • 538
0 votes
0 answers
128 views

How to show that lattice of subgroups D4 isn't modular lattice?

Here is a lattice of subgroups D4. The lattice isn't modular iff there is a "pentagon" as a sublattice. As we can see $\left \{ \rho_{0} \right\} - \left \{ \rho_{0}, \mu_1 \right\} - \left ...
Miganyshi's user avatar
  • 125
0 votes
1 answer
28 views

Is there any kind of distributive law for $c\cdot\max(a,b)$, allowing both signs of $c$?

Notation: For any two numbers $a$ and $b$, let the maximum be $a\sqcap b$, and let the minimum be $a\sqcup b$. (No, my symbols aren't upside-down. Compare this with floor notation; $\lfloor a\rfloor\...
mr_e_man's user avatar
  • 5,726
1 vote
0 answers
37 views

Contracting a segment in a Lattice

Studying lattices, I'm looking for the following construction: Given a finite (hence bounded and complete) lattice $L$ and $a,b \in L$ such that $a\leq b$, obtain a lattice $L'$ by "contracting&...
Simon Guilloud's user avatar
1 vote
0 answers
100 views

Multiplicative lattice with $(a \land b)\ast(a\lor b)=a \ast b$

The natural numbers $\mathbb{N}$ carry two (order-theoretic) lattice structures: One, say $L_1$, is the division lattice (where the join is the least common multiple and the meet is the greatest ...
Margaret's user avatar
  • 1,769
2 votes
1 answer
77 views

Algebraic structures with opposite subalgebra lattices and congruence lattices that are not groups with operators

Are there any algebraic structures where the congruence lattice and subalgebra lattice are opposites that do not look like groups with operators? My motivation for this question is noticing that ...
Greg Nisbet's user avatar
  • 11.9k
1 vote
1 answer
114 views

Database of lattices and lattice properties

Are there any websites that are databases of lattices? I'm also interested in databases distributed as libraries in a programming language or similar. I'm studying a little bit of lattice theory on ...
Greg Nisbet's user avatar
  • 11.9k
0 votes
0 answers
42 views

Is there an infinite version of the brute-force lattice congruence representation algorithm that succeeds?

I am interested in the congruence lattices of algebraic structures. Is there a brute-force way to produce an infinite algebraic structure whose lattice of congruences is isomorphic to some given ...
Greg Nisbet's user avatar
  • 11.9k
3 votes
0 answers
53 views

How does one go about "finding" the algebra of a particular logic?

My question is this: If I know a deductive system for a logic is there a simple way to derive the appropriate algebra for that system? For example: I start with the natural deduction system for ...
V. Jackson's user avatar
3 votes
1 answer
44 views

Stone's criterion for distributive lattices

A lattice $L$ is distributive iff for every $a\ne b$ in $L$ there is a prime ideal $P\in\textrm{Spec}(L)$ s.t. either $a\in P\not\ni b$ or $b\in P\not\ni a.$ Right to left. Since $D:L\to2^{\textrm{...
Maxim Nikitin's user avatar

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