First order theory for a given sentential logic












1












$begingroup$


Is it possible to extract the axioms and inference rules of a sentential/zeroth-order logic into a first order theory? Does this kind of "hoisting" have a name?



I'm trying to figure out how to check whether a finitely-valued sentential logic is consistent with an arbitrary collection of axioms and inference rules. I'd like to, if possible, use the same machinery for checking both the axioms and the inference rules.



I think that's equivalent to asking if the finitely-valued semantics is complete. I'm not trying to tackle soundness with this construction.



Let bold ($mathbf{I}$) Łukasiewicz-style operators represent logical connectives in the finitely-valued sentential logic under examination and $land, lor, to$ represent connectives in classical logic. $mathbf{I}$ is a logical symbol in the logic under examination, but a function symbol in the first-order theory.



Modus ponens in logic under examination:



$$ frac{a ;;text{and};; mathbf{I} a b}{b} $$



Weakining (as a tautology)



$$ frac{cdot}{mathbf{I}amathbf{I}ba} $$



Written as laws in a first order theory with $D$ being the domain of truth values in the logic under examination and $T$ being a predicate that identifies designated truth values in $D$ .



"Hoisting" of modus ponens. Because it's an inference rule, we consider the truth-ness of the premises and the conclusion independently.



$$ forall ab mathop{:} D mathop{.} ; T(a) land T(mathbf{I}ab) to T(b) $$



"Hoisting" of weakening. Because it's only intended to be a tautology, we check the truth-ness of the expression at the very end.



$$ forall a b mathop{:} D mathop{.} ; T[mathbf{I}amathbf{I}ba] $$










share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    As an aside to my answer below: what you call "implication introduction" is usually known as "weakening". "Implication introduction" is usually used as the name of an inference rule in natural deduction.
    $endgroup$
    – Rob Arthan
    Dec 9 '18 at 22:25
















1












$begingroup$


Is it possible to extract the axioms and inference rules of a sentential/zeroth-order logic into a first order theory? Does this kind of "hoisting" have a name?



I'm trying to figure out how to check whether a finitely-valued sentential logic is consistent with an arbitrary collection of axioms and inference rules. I'd like to, if possible, use the same machinery for checking both the axioms and the inference rules.



I think that's equivalent to asking if the finitely-valued semantics is complete. I'm not trying to tackle soundness with this construction.



Let bold ($mathbf{I}$) Łukasiewicz-style operators represent logical connectives in the finitely-valued sentential logic under examination and $land, lor, to$ represent connectives in classical logic. $mathbf{I}$ is a logical symbol in the logic under examination, but a function symbol in the first-order theory.



Modus ponens in logic under examination:



$$ frac{a ;;text{and};; mathbf{I} a b}{b} $$



Weakining (as a tautology)



$$ frac{cdot}{mathbf{I}amathbf{I}ba} $$



Written as laws in a first order theory with $D$ being the domain of truth values in the logic under examination and $T$ being a predicate that identifies designated truth values in $D$ .



"Hoisting" of modus ponens. Because it's an inference rule, we consider the truth-ness of the premises and the conclusion independently.



$$ forall ab mathop{:} D mathop{.} ; T(a) land T(mathbf{I}ab) to T(b) $$



"Hoisting" of weakening. Because it's only intended to be a tautology, we check the truth-ness of the expression at the very end.



$$ forall a b mathop{:} D mathop{.} ; T[mathbf{I}amathbf{I}ba] $$










share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    As an aside to my answer below: what you call "implication introduction" is usually known as "weakening". "Implication introduction" is usually used as the name of an inference rule in natural deduction.
    $endgroup$
    – Rob Arthan
    Dec 9 '18 at 22:25














1












1








1





$begingroup$


Is it possible to extract the axioms and inference rules of a sentential/zeroth-order logic into a first order theory? Does this kind of "hoisting" have a name?



I'm trying to figure out how to check whether a finitely-valued sentential logic is consistent with an arbitrary collection of axioms and inference rules. I'd like to, if possible, use the same machinery for checking both the axioms and the inference rules.



I think that's equivalent to asking if the finitely-valued semantics is complete. I'm not trying to tackle soundness with this construction.



Let bold ($mathbf{I}$) Łukasiewicz-style operators represent logical connectives in the finitely-valued sentential logic under examination and $land, lor, to$ represent connectives in classical logic. $mathbf{I}$ is a logical symbol in the logic under examination, but a function symbol in the first-order theory.



Modus ponens in logic under examination:



$$ frac{a ;;text{and};; mathbf{I} a b}{b} $$



Weakining (as a tautology)



$$ frac{cdot}{mathbf{I}amathbf{I}ba} $$



Written as laws in a first order theory with $D$ being the domain of truth values in the logic under examination and $T$ being a predicate that identifies designated truth values in $D$ .



"Hoisting" of modus ponens. Because it's an inference rule, we consider the truth-ness of the premises and the conclusion independently.



$$ forall ab mathop{:} D mathop{.} ; T(a) land T(mathbf{I}ab) to T(b) $$



"Hoisting" of weakening. Because it's only intended to be a tautology, we check the truth-ness of the expression at the very end.



$$ forall a b mathop{:} D mathop{.} ; T[mathbf{I}amathbf{I}ba] $$










share|cite|improve this question











$endgroup$




Is it possible to extract the axioms and inference rules of a sentential/zeroth-order logic into a first order theory? Does this kind of "hoisting" have a name?



I'm trying to figure out how to check whether a finitely-valued sentential logic is consistent with an arbitrary collection of axioms and inference rules. I'd like to, if possible, use the same machinery for checking both the axioms and the inference rules.



I think that's equivalent to asking if the finitely-valued semantics is complete. I'm not trying to tackle soundness with this construction.



Let bold ($mathbf{I}$) Łukasiewicz-style operators represent logical connectives in the finitely-valued sentential logic under examination and $land, lor, to$ represent connectives in classical logic. $mathbf{I}$ is a logical symbol in the logic under examination, but a function symbol in the first-order theory.



Modus ponens in logic under examination:



$$ frac{a ;;text{and};; mathbf{I} a b}{b} $$



Weakining (as a tautology)



$$ frac{cdot}{mathbf{I}amathbf{I}ba} $$



Written as laws in a first order theory with $D$ being the domain of truth values in the logic under examination and $T$ being a predicate that identifies designated truth values in $D$ .



"Hoisting" of modus ponens. Because it's an inference rule, we consider the truth-ness of the premises and the conclusion independently.



$$ forall ab mathop{:} D mathop{.} ; T(a) land T(mathbf{I}ab) to T(b) $$



"Hoisting" of weakening. Because it's only intended to be a tautology, we check the truth-ness of the expression at the very end.



$$ forall a b mathop{:} D mathop{.} ; T[mathbf{I}amathbf{I}ba] $$







logic






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Dec 9 '18 at 22:26







Gregory Nisbet

















asked Dec 9 '18 at 19:31









Gregory NisbetGregory Nisbet

756612




756612








  • 1




    $begingroup$
    As an aside to my answer below: what you call "implication introduction" is usually known as "weakening". "Implication introduction" is usually used as the name of an inference rule in natural deduction.
    $endgroup$
    – Rob Arthan
    Dec 9 '18 at 22:25














  • 1




    $begingroup$
    As an aside to my answer below: what you call "implication introduction" is usually known as "weakening". "Implication introduction" is usually used as the name of an inference rule in natural deduction.
    $endgroup$
    – Rob Arthan
    Dec 9 '18 at 22:25








1




1




$begingroup$
As an aside to my answer below: what you call "implication introduction" is usually known as "weakening". "Implication introduction" is usually used as the name of an inference rule in natural deduction.
$endgroup$
– Rob Arthan
Dec 9 '18 at 22:25




$begingroup$
As an aside to my answer below: what you call "implication introduction" is usually known as "weakening". "Implication introduction" is usually used as the name of an inference rule in natural deduction.
$endgroup$
– Rob Arthan
Dec 9 '18 at 22:25










1 Answer
1






active

oldest

votes


















1












$begingroup$

Yes, it is usually possible to model a propositional logic as a first-order theory whose domain of discourse represents the set of truth-values in the propositional logic and whose axioms represent the propositional axioms and inference rules. (I say "usually" because you could devise a bizarre propositional logic with side-conditions on the inference rules that would make them hard to model.)



I don't know of a name for this process in general, but for a large class of propositional logics, the first-order theory will be an equational theory of the sort studied in universal algebra, and the process amounts to giving an algebraic semantics for the logic. E.g., classical propositional logic corresponds to the theory of Boolean algebras and intuitionistic propositional logic corresponds to the theory of Heyting algebras.






share|cite|improve this answer









$endgroup$













    Your Answer





    StackExchange.ifUsing("editor", function () {
    return StackExchange.using("mathjaxEditing", function () {
    StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
    StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
    });
    });
    }, "mathjax-editing");

    StackExchange.ready(function() {
    var channelOptions = {
    tags: "".split(" "),
    id: "69"
    };
    initTagRenderer("".split(" "), "".split(" "), channelOptions);

    StackExchange.using("externalEditor", function() {
    // Have to fire editor after snippets, if snippets enabled
    if (StackExchange.settings.snippets.snippetsEnabled) {
    StackExchange.using("snippets", function() {
    createEditor();
    });
    }
    else {
    createEditor();
    }
    });

    function createEditor() {
    StackExchange.prepareEditor({
    heartbeatType: 'answer',
    autoActivateHeartbeat: false,
    convertImagesToLinks: true,
    noModals: true,
    showLowRepImageUploadWarning: true,
    reputationToPostImages: 10,
    bindNavPrevention: true,
    postfix: "",
    imageUploader: {
    brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
    contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
    allowUrls: true
    },
    noCode: true, onDemand: true,
    discardSelector: ".discard-answer"
    ,immediatelyShowMarkdownHelp:true
    });


    }
    });














    draft saved

    draft discarded


















    StackExchange.ready(
    function () {
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3032848%2ffirst-order-theory-for-a-given-sentential-logic%23new-answer', 'question_page');
    }
    );

    Post as a guest















    Required, but never shown

























    1 Answer
    1






    active

    oldest

    votes








    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    1












    $begingroup$

    Yes, it is usually possible to model a propositional logic as a first-order theory whose domain of discourse represents the set of truth-values in the propositional logic and whose axioms represent the propositional axioms and inference rules. (I say "usually" because you could devise a bizarre propositional logic with side-conditions on the inference rules that would make them hard to model.)



    I don't know of a name for this process in general, but for a large class of propositional logics, the first-order theory will be an equational theory of the sort studied in universal algebra, and the process amounts to giving an algebraic semantics for the logic. E.g., classical propositional logic corresponds to the theory of Boolean algebras and intuitionistic propositional logic corresponds to the theory of Heyting algebras.






    share|cite|improve this answer









    $endgroup$


















      1












      $begingroup$

      Yes, it is usually possible to model a propositional logic as a first-order theory whose domain of discourse represents the set of truth-values in the propositional logic and whose axioms represent the propositional axioms and inference rules. (I say "usually" because you could devise a bizarre propositional logic with side-conditions on the inference rules that would make them hard to model.)



      I don't know of a name for this process in general, but for a large class of propositional logics, the first-order theory will be an equational theory of the sort studied in universal algebra, and the process amounts to giving an algebraic semantics for the logic. E.g., classical propositional logic corresponds to the theory of Boolean algebras and intuitionistic propositional logic corresponds to the theory of Heyting algebras.






      share|cite|improve this answer









      $endgroup$
















        1












        1








        1





        $begingroup$

        Yes, it is usually possible to model a propositional logic as a first-order theory whose domain of discourse represents the set of truth-values in the propositional logic and whose axioms represent the propositional axioms and inference rules. (I say "usually" because you could devise a bizarre propositional logic with side-conditions on the inference rules that would make them hard to model.)



        I don't know of a name for this process in general, but for a large class of propositional logics, the first-order theory will be an equational theory of the sort studied in universal algebra, and the process amounts to giving an algebraic semantics for the logic. E.g., classical propositional logic corresponds to the theory of Boolean algebras and intuitionistic propositional logic corresponds to the theory of Heyting algebras.






        share|cite|improve this answer









        $endgroup$



        Yes, it is usually possible to model a propositional logic as a first-order theory whose domain of discourse represents the set of truth-values in the propositional logic and whose axioms represent the propositional axioms and inference rules. (I say "usually" because you could devise a bizarre propositional logic with side-conditions on the inference rules that would make them hard to model.)



        I don't know of a name for this process in general, but for a large class of propositional logics, the first-order theory will be an equational theory of the sort studied in universal algebra, and the process amounts to giving an algebraic semantics for the logic. E.g., classical propositional logic corresponds to the theory of Boolean algebras and intuitionistic propositional logic corresponds to the theory of Heyting algebras.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Dec 9 '18 at 22:23









        Rob ArthanRob Arthan

        29.5k42967




        29.5k42967






























            draft saved

            draft discarded




















































            Thanks for contributing an answer to Mathematics Stack Exchange!


            • Please be sure to answer the question. Provide details and share your research!

            But avoid



            • Asking for help, clarification, or responding to other answers.

            • Making statements based on opinion; back them up with references or personal experience.


            Use MathJax to format equations. MathJax reference.


            To learn more, see our tips on writing great answers.




            draft saved


            draft discarded














            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3032848%2ffirst-order-theory-for-a-given-sentential-logic%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown





















































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown

































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown







            Popular posts from this blog

            How to change which sound is reproduced for terminal bell?

            Title Spacing in Bjornstrup Chapter, Removing Chapter Number From Contents

            Can I use Tabulator js library in my java Spring + Thymeleaf project?