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3 votes
0 answers
91 views

Algebraic logical structure

Let $M=(W,R)$ be a Kripke frame, $A=(f_1,...,f_m)$ is a tuple of operations $f_i:W^{n_i}\to W$, and $\Phi=(\varphi_1,...,\varphi_m )$ is a tuple of first-order logic formulas in vocabulary $\sigma=\{=...
Ben Tom's user avatar
  • 107
2 votes
0 answers
109 views

Function and algebraic system

Let $f$ be a surjective function from $X$ to $\{1,2,3\}$. Let $* :X^2 \to X$, such that $$f(x)\neq f(y) \implies f(x) \neq f(xy)\neq f(y), $$ and $$f(x)=f(y)\implies f(x)=f(xy).$$ Let's call the ...
Ben Tom's user avatar
  • 107
11 votes
1 answer
462 views

Invariant theory in universal algebra

Let $\mathcal{L}$ be a finite first-order language with no relation symbols and let $\mathcal{K}:=\mathcal{V}(\Theta)$ be a variety in this language defined by a set of identities $\Theta$. My ...
jg1896's user avatar
  • 3,318
4 votes
1 answer
214 views

The question about elementary equivalence of free products

Let $A,B,C,D$ be algebraic systems and $A$ and $B$ be elementary equivalent as well as $C$ and $D$. Are free products of $A,C$ and $B,D$ elementary equivalent if $A,B,C,D$ are groups, or $A,B,C,D$ ...
Evgeny's user avatar
  • 41
5 votes
0 answers
188 views

Algebraic/relational structures produced using evolutionary/machine learning algorithms?

Are there examples of algebraic structures which have been constructed using evolutionary algorithms and possibly machine learning algorithms? I am looking for algebraic structures like lattices ...
Joseph Van Name's user avatar
5 votes
1 answer
245 views

What are algebraic systems and algebraic closure as defined by Kenjiro Shoda? Which are his main results on them?

In On Utumi's ring of quotients, Canad. J. Math. 15(1963), 363-370, J. Lambek says: As a matter of historical record, the minimal injective extension of a module is a special case of the "algebraic ...
Jose Brox's user avatar
  • 2,992
7 votes
0 answers
401 views

Universal anti-Horn classes?

Is there published work about universal anti-Horn classes? Anti-Horn formulas are also sometimes known as dual Horn. See also related question Is there any research of universal algebras axiomatized ...
András Salamon's user avatar
6 votes
1 answer
676 views

Generalizations of Birkhoff's HSP Theorem

Let $\mathbf{C}$ be the class of algebraic structures of some fixed type satisfying some sentence $\phi$. Birkhoff's HSP theorem says that $\mathbf{C}$ is closed under homomorphisms, subalgebras and ...
Tristan Bice's user avatar
  • 1,307
5 votes
2 answers
974 views

Shape of axioms in algebraic structures

When defining algebraic structures (like monoids, groups, etc...), are there some constraints on the shape of the axioms, for the structure to have good properties that we implicitly use in many ...
Denis's user avatar
  • 1,341