Non-classical logic | Paraconsistent logic | Substructural logic

Relevance logic

Relevance logic, also called relevant logic, is a kind of non-classical logic requiring the antecedent and consequent of implications to be relevantly related. They may be viewed as a family of substructural or modal logics. It is generally, but not universally, called relevant logic by British and, especially, Australian logicians, and relevance logic by American logicians. Relevance logic aims to capture aspects of implication that are ignored by the "material implication" operator in classical truth-functional logic, namely the notion of relevance between antecedent and conditional of a true implication. This idea is not new: C. I. Lewis was led to invent modal logic, and specifically strict implication, on the grounds that classical logic grants paradoxes of material implication such as the principle that a falsehood implies any proposition. Hence "if I'm a donkey, then two and two is four" is true when translated as a material implication, yet it seems intuitively false since a true implication must tie the antecedent and consequent together by some notion of relevance. And whether or not the speaker is a donkey seems in no way relevant to whether two and two is four. How does relevance logic formally capture a notion of relevance? In terms of a syntactical constraint for a propositional calculus, it is necessary, but not sufficient, that premises and conclusion share atomic formulae (formulae that do not contain any logical connectives). In a predicate calculus, relevance requires sharing of variables and constants between premises and conclusion. This can be ensured (along with stronger conditions) by, e.g., placing certain restrictions on the rules of a natural deduction system. In particular, a Fitch-style natural deduction can be adapted to accommodate relevance by introducing tags at the end of each line of an application of an inference indicating the premises relevant to the conclusion of the inference. Gentzen-style sequent calculi can be modified by removing the weakening rules that allow for the introduction of arbitrary formulae on the right or left side of the sequents. A notable feature of relevance logics is that they are paraconsistent logics: the existence of a contradiction will not cause "explosion". This follows from the fact that a conditional with a contradictory antecedent that does not share any propositional or predicate letters with the consequent cannot be true (or derivable). (Wikipedia).

Video thumbnail

Relevance model 1: Bernoulli sets vs. multinomial urns

[http://bit.ly/RModel] Relevance model is the language model of the relevant class. In this video we look at the difference between the multinomial model (the one used in relevance models) and the multiple-Bernoulli model, which forms the basis for the classical probabilistic models.

From playlist IR18 Relevance Model

Video thumbnail

Relevance model 4: Bayesian interpretation

[http://bit.ly/RModel] Another way to interpret the relevance model is via Bayesian estimation: the relevance model could be one of a large set of urns. We know what the urns are, but don't know which one is correct, so we compute the posterior probability for each candidate urn, and combi

From playlist IR18 Relevance Model

Video thumbnail

Relevance model 5: summary of assumptions

[http://bit.ly/RModel] The relevance model ranking is based on the probability ranking principle (PRP). It uses the background (corpus) model as a language model for the non-relevant class (just like the classical model), but has a novel estimate for the relevance model. The estimate is ba

From playlist IR18 Relevance Model

Video thumbnail

Evaluation 5: relevance judgments

Relevance judgments indicate which documents are relevant to the information need of a user. They are constructed by trained annotators inspecting a subset of documents (typically pooled across a large number of different retrieval algorithms).

From playlist IR13 Evaluating Search Engines

Video thumbnail

Logic: The Structure of Reason

As a tool for characterizing rational thought, logic cuts across many philosophical disciplines and lies at the core of mathematics and computer science. Drawing on Aristotle’s Organon, Russell’s Principia Mathematica, and other central works, this program tracks the evolution of logic, be

From playlist Logic & Philosophy of Mathematics

Video thumbnail

Relevance model 2: the sampling game

[http://bit.ly/RModel] How can we estimate the language model of the relevant class if we have no examples of relevant documents? We play a sampling game as follows. The relevance model is an urn with unknown parameters. We draw several samples from it and observe the query. What is the pr

From playlist IR18 Relevance Model

Video thumbnail

Relevance model 7: ranking functions

[http://bit.ly/RModel] The probability ranking principle (PRP) seems like the obvious ranking function for relevance models, but when we use it in the form of the odds ratio (as in the classical model), we bias our rankings towards the wrong type of document. A better approach is to use th

From playlist IR18 Relevance Model

Video thumbnail

Introduction to Predicate Logic

This video introduces predicate logic. mathispower4u.com

From playlist Symbolic Logic and Proofs (Discrete Math)

Video thumbnail

Wolfram Physics Project: Working Session Tuesday, Mar. 16, 2021 [Bibliographying Combinators]

This is a Wolfram Physics Project working session on bibliographying combinators. Begins at 4:33 Originally livestreamed at: https://twitch.tv/stephen_wolfram Stay up-to-date on this project by visiting our website: http://wolfr.am/physics Check out the announcement post: http://wolfr.am

From playlist Wolfram Physics Project Livestream Archive

Video thumbnail

Introduction to Philosophy and Logic

Humans are on a quest to understand the world around us. How did this quest begin? What are the tools we use to gather knowledge? How do we know what is possible to know? What do we mean when using words like ethics, ontology, metaphysics, aesthetics, and logic? This series is going to get

From playlist Philosophy/Logic

Video thumbnail

Wittgenstein Changes His Mind

A talk given by Cora Diamond in 2017 at St. John's College. 00:00 Wittgenstein as a Responsive Philosopher 04:18 Wittgenstein reads Russell 13:24 Wittgenstein & the Spirit of Modernity 20:05 What Next? The Tractatus 30:20 Flaws in the Tractatus 34:23 Wittgenstein’s Diagnosis 41:39 O

From playlist Wittgenstein

Video thumbnail

Exercises in COMPLEX TRUTH TREES - Logic

In this video in #Logic / #PhilosophicalLogic we do two examples of complex truth trees and then I give general strategies for doing these. The trees here use rules for negation, conjunction, disjunction, the conditional, and the biconditional. 0:00 [Example #1] 4:53 [Example #2] 9:29 [St

From playlist Logic in Philosophy and Mathematics

Video thumbnail

mod-27 lec-28 Logic Circuits

Fundamentals of Industrial Oil Hydraulics and Pneumatics by Prof. R.N. Maiti,Department of Mechanical Engineering,IIT Kharagpur.For more details on NPTEL visit http://nptel.ac.in

From playlist IIT Kharagpur: Fundamentals of Industrial Oil Hydraulics and Pneumatics (CosmoLearning Mechanical Engineering)

Video thumbnail

Excel Magic Trick 455: Advanced Filter Macro: Extract Grant Records Under A Cumulative Total

Download Files: https://people.highline.edu/mgirvin/YouTubeExcelIsFun/EMT453-457.xls See how to extract grant records with highest point value and only extract enough records collectively that are under the Total Funding Ceiling: 1.AND function for 2 criteria 2.Running Total Formula w

From playlist Excel Recorded Macros - Excel Macro Recorder

Video thumbnail

Live CEOing Ep 223: Temporal Logic in Wolfram Language

Watch Stephen Wolfram and teams of developers in a live, working, language design meeting. This episode is about Temporal Logic in the Wolfram Language.

From playlist Behind the Scenes in Real-Life Software Design

Video thumbnail

O'Reilly Webcast: View Updating: How to Make it Work

Ever since the relational view concept was first invented, view updating has been a contentious issue. Support in today's SQL products is ad hoc and meager at best. The SQL standard is even more impenetrable in this area than it usually is. Even the research literature is weak on this topi

From playlist O'Reilly Webcasts 2

Video thumbnail

The measurement problem and some mild solutions by Dustin Lazarovici (Lecture - 04)

21 November 2016 to 10 December 2016 VENUE Ramanujan Lecture Hall, ICTS Bangalore Quantum Theory has passed all experimental tests, with impressive accuracy. It applies to light and matter from the smallest scales so far explored, up to the mesoscopic scale. It is also a necessary ingredie

From playlist Fundamental Problems of Quantum Physics

Video thumbnail

LambdaConf 2015 - Type Theory and its Meaning Explanations Jon Sterling

At the heart of intuitionistic type theory lies an intuitive semantics called the “meaning explanations." Crucially, when meaning explanations are taken as definitive for type theory, the core notion is no longer “proof” but “verification”. We’ll explore how type theories of this sort aris

From playlist LambdaConf 2015

Related pages

Natural deduction | Connexive logic | Paradoxes of material implication | Alonzo Church | Substructural logic | C. I. Lewis | Lattice (order) | Identity element | Principle of explosion | Propositional calculus | Wilhelm Ackermann | Vacuous truth | Predicate calculus | Atomic formula | Sequent calculus | Material conditional | Homomorphism | Consequent | Antecedent (logic) | Sequent | Substructural type system | Modal logic | Associative property | De Morgan algebra | Commutative property | Residuated lattice | Paraconsistent logic | Logical connective | Classical logic | Monoid