Questions tagged [algebraic-logic]

Use this tag for questions related to reasoning obtained by manipulating equations with free variables.

Algebraic logic is reasoning obtained by manipulating equations with free variables.

What is now usually called classical algebraic logic focuses on identification and algebraic description of models for the study of (1) various logics in the form of classes of that constitute the algebraic semantics for those deductive systems and (2) connected problems like representation and duality. Well known results, such as the representation theorem in and Stone duality, fall under the umbrella of classical algebraic logic.

Work in the more recent abstract algebraic logic focuses on the process of algebraization itself, for example, classification of various forms of algebraizability using the Leibniz operator.

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Which texts do you recommend to study universal algebra and lattice theory?

As I'm planning to study some algebraic logic (a lot of!), I found that some knowledge of universal algebra, lattice theory and boolean algebras is a must. I wonder if you have any recommendation to study from to be well-prepared to study algebraic…
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Is it known whether Free Complete Heyting Algebras Exist?

I was reading the wikipedia page for heyting algebras, and it made the claim that "it is unknown whether free complete heyting algebras exist". It came unsourced, but by tracking the edit I was able to source the claim to page 34~35 of Stone Spaces…
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Is there any duality for distributive lattices?

Dual to bounded distributive lattices are Priestley spaces, and that for Heyting algebras are Esakia spaces. Do we have such results for the class of lattices which are not bounded in general, preferably for distributive lattices or…
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Boolean valued models in a general setting

It is well known that Boolean valued models play significant roles for set-theoretic purposes. But how well-studied are Boolean valued models in a more general setting, as models for random first-order languages? For example, towards the end of…
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Understanding the meaning of "soundness" and "completeness" in the context of Algebraic Logic

I'm reading this PDF as a further study from my Modal Logic course. I had no previous experience with algebraic logic before, so I'm having a bit of trouble understanding the exact meaning of Corollary 2.17 at page 35, which states: Corollary 2.17…
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Equational axioms for quantifiers

I seek an equational axiomatization of the quantifiers of predicate logic (that permits empty domains). Start with the equational axioms for Boolean algebra. Add the following axioms, which come in dual pairs: Renaming (for $y$ not free in…
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Intermediate logics and strong algebraic completeness

As a setup, suppose that you have a usual propositional language $\mathcal L$ over a set of propositional variables $Var$ and with symbols $\land,\lor,\rightarrow,\bot$ in the usual way. Let $L$ be an intermediate logic over $\mathcal L$, that is a…
user369816
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Does the relation algebra have a sole sufficient operator?

In brief, does the relation algebra (defined here axiomatically) have a sole sufficient operator? Given a set $D$, define operators $^{-}$, $\wedge$, $^{c}$, $\bullet $ on the set $\mathcal{P}(D^{2})$ as follows: $$ \begin{align} R^{-} &= \{ (x,y)…
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Connection between Boolean and Heyting algebras as models and as Lindenbaum-Tarski algebras

I'm a bit confused about the role of Boolean/Heyting algebras in logic. It seems to me that there are two different facets of their usage that I'm trying to reconcile. The first one is the usual construction of a Boolean/Heyting algebra from…
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What is the point of algebraic logic?

The question is worded a bit unfortunately. Honestly, I find algebraic logic to be one of the most interesting subjects I've ever encountered. But I find myself unable to articulate why it's interesting, other than for its own sake. Is there any…
user279406
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Studying Algebraic Logic from Plotkin's Universal Algebra, Algebraic Logic, and Databases.

I wonder what do you think about this book Universal Algebra, Algebraic Logic, and Databases? I've looked for some reviews but found none so I can not determine if it's fine to learn about polyadic algebras and algebraic logic from or not. I've…
FNH
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Is this generalization of Boolean algebras a variety?

I'm interested in the class of structures $\langle S,\top,\neg,\wedge\rangle$ defined by the axioms: $p \wedge q=q \wedge p$ $p \wedge (q \wedge r) = (p\wedge q)\wedge r$ $p = p \wedge p$ $p = \neg\neg p$ $p \vee(q\wedge r) = (p\vee q)\wedge(p\vee…
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Good recommendations to study Algebraic logic

I've asked before about good recommendations to study algebra for the sake of algebraic logic and I've got very good recommendations. I wonder if you have some recommendations to start studying algeraic logic itself. I've come across some books but…
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Relationship between measure theory and quantification

In a 1978 paper published by David P. Ellerman and Gian-Carlo Rota, the duo discuss the relationship(s) exhibited by measure theory, probability theory, and logic paying special attention to how these concepts apply to describing the nature of…
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Weakening of projectivity for Boolean algebras independent from projectivity

We say that a Boolean algebra $B$ is projective if for all Boolean algebras $C$ and $D$, if $f:C\to D$ is an onto homomorphism, and $g:B\to D$ is any homomorphism, there is some homomorphism $h:B\to C$ making the obvious triangle commute. As an…
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