Archive for the ‘Logic’ Category

Logic and Probabilistic Programming

Friday, March 29th, 2013

Programming Trends to Watch: Logic and Probabilistic Programming by Dean Wampler.

From the post:

I believe there are two other emerging trends in programming worth watching that will impact the data world.

Logic Programming, like FP, is actually not new at all, but it is seeing a resurgence of interest, especially in the Clojure community. Rules engines, like Drools, are an example category of logic programming that has been in use for a long time.

…

We’re on the verge of moving to the next level, probabilistic programming languages and systems that make it easier to build probabilistic models, where the modeling concepts are promoted to first-class primitives in new languages, with underlying runtimes that do the hard work of inferring answers, similar to the way that logic programming languages work already. The ultimate goal is to enable end users with limited programming skills, like domain experts, to build effective probabilistic models, without requiring the assistance of Ph.D.-level machine learning experts, much the way that SQL is widely used today.

DARPA, the research arm of the U.S. Department of Defense, considers this trend important enough that they are starting an initiative to promote it, called Probabilistic Programming for Advanced Machine Learning, which is also described in this Wired article.

Registration for the DARPA event (April 10, 2013) is closed but a video recording will be posted at: http://www.darpa.mil/Opportunities/Solicitations/I2O_Solicitations.aspx after April 10, 2013.

I suspect semantics are going to be at issue in any number of ways.

The ability to handle semantics robustly may be of value.

Posted in Logic, Probabilistic Programming | 1 Comment »

Logic and Lattices for Distributed Programming

Wednesday, January 30th, 2013

Logic and Lattices for Distributed Programming

From the post:

Neil Conway from Berkeley CS is giving an advanced level talk at a meetup today in San Francisco on a new paper: Logic and Lattices for Distributed Programming – extending set logic to support CRDT-style lattices.

The description of the meetup is probably the clearest introduction to the paper:

Developers are increasingly choosing datastores that sacrifice strong consistency guarantees in exchange for improved performance and availability. Unfortunately, writing reliable distributed programs without the benefit of strong consistency can be very challenging.

….

In this talk, I’ll discuss work from our group at UC Berkeley that aims to make it easier to write distributed programs without relying on strong consistency. Bloom is a declarative programming language for distributed computing, while CALM is an analysis technique that identifies programs that are guaranteed to be eventually consistent. I’ll then discuss our recent work on extending CALM to support a broader range of programs, drawing upon ideas from CRDTs (A Commutative Replicated Data Type).

If you have an eye towards understanding the future then this is for you.

Do note that the Bloom language is treated more extensively in Datalog Reloaded. You may recall that the basis for tolog (a topic map query language) was Datalog.

Posted in Bloom Language, Datalog, Distributed Systems, Logic, tolog | No Comments »

Jurimetrics (Modern Uses of Logic in Law (MULL))

Tuesday, October 23rd, 2012

Jurimetrics (Modern Uses of Logic in Law (MULL))

From the about page:

Jurimetrics, The Journal of Law, Science, and Technology (ISSN 0897-1277), published quarterly, is the journal of the American Bar Association Section of Science & Technology Law and the Center for Law, Science & Innovation. Click here to view the online version of Jurimetrics.

Jurimetrics is a forum for the publication and exchange of ideas and information about the relationships between law, science and technology in all areas, including:

  • Physical, life and social sciences
  • Engineering, aerospace, communications and computers
  • Logic, mathematics and quantitative methods
  • The uses of science and technology in law practice, adjudication and court and agency administration
  • Policy implications and legislative and administrative control of science and technology.

Jurimetrics was first published in 1959 under the leadership of Layman Allen as Modern Uses of Logic in Law (MULL). The current name was adopted in 1966. Jurimetrics is the oldest journal of law and science in the United States, and it enjoys a circulation of more than 8,000, which includes all members of the ABA Section of Science & Technology Law.

I just mentioned this journal in Wyner et al.: An Empirical Approach to the Semantic Representation of Laws, but wanted to also capture its earlier title, Modern Uses of Logic in Law (MULL), because I am likely to search for it as well.

I haven’t looked at the early issues in some years but as I recall, they were quite interesting.

Posted in Law, Legal Informatics, Logic, Semantics | No Comments »

Video about a Problem of Inductive Arguments

Sunday, July 29th, 2012

Video about a Problem of Inductive Arguments from Dr. Adam Wyner.

From the post:

A nice cartoon illustration of the problem with inductive arguments in a social context. A video on youtube, so there is an ad popup. Best watched as a loop to appreciate the full point:

Makes me wish I knew how to do animation.

Will make you re-consider the use of induction in your topic map!

Posted in Induction, Logic | No Comments »

Exploring the rationality of some syntactic merging operators (extended version)

Sunday, July 29th, 2012

Exploring the rationality of some syntactic merging operators (extended version) by José Luis Chacón and Ramón Pino Pérez

Abstract:

Most merging operators are defined by semantics methods which have very high computational complexity. In order to have operators with a lower computational complexity, some merging operators defined in a syntactical way have be proposed. In this work we define some syntactical merging operators and exploring its rationality properties. To do that we constrain the belief bases to be sets of formulas very close to logic programs and the underlying logic is defined through forward chaining rule (Modus Ponens). We propose two types of operators: arbitration operators when the inputs are only two bases and fusion with integrity constraints operators. We introduce a set of postulates inspired of postulates LS, proposed by Liberatore and Shaerf and then we analyzed the first class of operators through these postulates. We also introduce a set of postulates inspired of postulates KP, proposed by Konieczny and Pino P\’erez and then we analyzed the second class of operators through these postulates.

Another paper on logic based merging.

I created a separate tag, “merging operators,” to distinguish this from the merging we experience with TMDM based topic maps.

The merging here refers to merging of beliefs to form a coherent view of the world.

A topic map, not subject to other constraints, can “merge” data about a subject that leads to different inferences or is even factually contradictory.

Even if logical consistency post-merging isn’t your requirement, this is a profitable paper to read.

I will see what other resources I can find on logic based merging.

Posted in Logic, Merging Operators | No Comments »

NoLogic (Not only Logic) – #5,000

Wednesday, June 20th, 2012

I took the precaution to say “Not only Logic” so I would not have to reach back and invent a soothing explanation for saying “NoLogic.”

The marketing reasons for parroting “NoSQL” are obvious and I won’t belabor them here.

There are some less obvious reasons for saying “NoLogic.”

Logic, as in formal logic (description logic for example), is rarely used by human user. Examples mainly exist in textbooks and journal articles. And of late, in semantic web proposals.

Ask anyone in your office to report the number of times they used formal logic to make a decision in the last week. We both know the most likely answer, by a very large margin.

But we rely upon searches everyday that are based upon the use of digital logic.

Searches that are quite useful in assisting non-logical users but we limit ourselves in refining those search results. By more logic. Which we don’t use ourselves.

Isn’t that odd?

Or take the “curse of dimensionality.” Viewed from the perspective of data mining, Baeza-Yates & Ribeiro-Neto point out that “…a large feature space might render document classifiers impractical.” p.320

Those are features that can be identified with the document.

What of the dimensions of a user who is a former lawyer, theology student, markup editor, Ancient Near Easter amateur, etc., all of which have an impact on how they view any particular document and its relevance to a search result? Or to make connections to another document?

Some of those dimensions would be shared by other users, some would not.

But in either case, human users are untroubled by the “curse of dimensionality.” In part I would suggest because “NoLogic” comes easy for the human user. We may not be able to articulate all the dimensions, but we are likely to pick results similar users will find useful.

We should not forgo logic, either as digital logic or formal reasoning systems, when those assist us.

We should be mindful that logic does not represent all views of the world.

In other words, not only logic (NoLogic).

Posted in Logic, Marketing | No Comments »

Mathematical Reasoning Group

Thursday, May 31st, 2012

Mathematical Reasoning Group

From the homepage:

The Mathematical Reasoning Group is a distributed research group based in the Centre for Intelligent Systems and their Applications, a research institute within the School of Informatics at the University of Edinburgh. We are a community of informaticists with interests in theorem proving, program synthesis and artificial intelligence. There is a more detailed overview of the MRG and a list of people. You can also find out how to join the MRG.

I was chasing down proceedings from prior “Large Heterogeneous Data” workshops (damn, that’s a fourth name), when I ran across this jewel as the location of some of the archives.

Has lots of other interesting papers, software, activities.

Sing out if you see something you think needs to appear on this blog.

Posted in Logic, Mathematical Reasoning, Mathematics | No Comments »

Rhetological Fallacies

Tuesday, April 3rd, 2012

Rhetological Fallacies: Errors and manipulations of rhetorical and logical thinking.

Useful and deeply amusing chart of errors in rhetoric and logic by David McCandless.

Each error has a symbol along with a brief explanation.

These symbols really should appear in Unicode. ;-)

Or at least have a TeX symbol set defined for them.

I have written to ask about a version with separate images/glyphs for each fallacy. Would make it easier to “tag” arguments.

Posted in Humor, Logic, Rhetoric | No Comments »

Multiple Recognitions

Tuesday, January 31st, 2012

Yesterday in The “L&O” Shortage I asked the question:

“…can something be recognized more than once?”

That may not be an artful way to frame the question. Perhaps better:

When an author uses some means for identification, whatever that may be, can it be recognized differently by different users?

One case that comes to mind in the interpretation of Egyptian Hieroglyphics over time. In addition to the attempts in the 16th and 17th centuries, which are now thought to be completely fantastic, there are the modern “accepted” translations as well as ancient Egyptian texts where it appears the scribe did not understand what was being copied.

If we are going to faithfully record the history of interpretation of such literature, we cannot flatten the “translated” texts to have the meanings we would assign to them today. The references of the then current literature would make no sense if we did.

Google Books is a valuable service but it is also a dangerous one for research purposes. In part because semantic drift occurs in any living language (or the interpretation of dead ones) and the results are reported without any warnings about such shifts.

Did you know, for example, that “cab” at one time was a slang reference to a house of prostitution? Would give new meaning to the statement: “I will call you a cab.” doesn’t it?

Before we can assign semantics to any word, we need to know what is being identified by that word. But knowing that any one word may represent multiple identifications.

Requirement: A system of identification must support the same identifiers resolving to different identifications.

The consequences of deciding otherwise on such a requirement, I will try to take up tomorrow.

Posted in Logic, Ontology, Semantics | 1 Comment »

The “L&O” Shortage

Monday, January 30th, 2012

Last week I mentioned that we are facing a critical shortage of both logicians and ontologists: Alarum – World Wide Shortage of Logicians and Ontologists.

This is the first of a number of posts on what we can do, facing this tidal wave of data with nary a logician or ontologist in sight.

I have a question that I think we need to answer before we get to the question of semantics.

Is it fair to say that identification comes before semantics? That is we have to recognize something (whatever that may be) before we can talk about its semantics?

I ask because I think it is important to take the requirements for data and its semantics one step at a time. And in particular to not jump ahead of ourselves with half-remembered bits of doggerel from grade school to propose syntactic solutions.

Or to put it differently, let’s make sure of what order steps need to be taken before we trip over our own feet.

That would be the requirements phase, as is well known to the successful programmers and startup folks among the audience.

So, is requirement #1 that something be recognized? Whether that is a file, format, subject of any sort or description. I don’t know but suspect we can’t even use logic on things we have yet to recognize.

Just to give you a hint about tomorrow or perhaps the next day, I have meetings tomorrow, can something be recognized more than once?

This may seem like a slow start but the time will pass more quickly than you think it will. There are a number of “perennial” issues that I will argue can be side-lined, in part because they have no answer other than personal preference.

Posted in Logic, Ontology | 1 Comment »

Alarum – World Wide Shortage of Logicians and Ontologists

Friday, January 27th, 2012

Did you know there is an alarming shortage of logicians and ontologists around the world? Apparently everywhere, in all countries.

Came as a complete shock/surprise to me.

I was reading ‘Digital Universe’ to Add 1.8 Zettabytes in 2011 by Rich Miller which says:

More than 1.8 zettabytes of information will be created and stored in 2011, according to the latest IDC Digital Universe Study sponsored by EMC. That’s a mind-boggling figure, equivalent to 1.8 trillion gigabytes -enough information to fill 57.5 billion 32GB Apple iPads. It also illustrates the challenge in storing and managing all that data.

But then I remembered the “state of the Semantic Web” report of 31,634,213,770 triples.

I know it is apples and oranges to some degree but compare the figures for data and linked data:

Data 1,800,000,000,000,000,000,000
Triples 31,634,213,770

Not to mention that the semantics of data is constantly evolving. If not business and scientific data, recall that “texting” was unknown little more than a decade ago.

It is clear that we don’t have enough logicians and ontologists (who have yet to agree on a common upper ontology) to keep up with the increasing flow of data. For that matter, the truth is they have been constantly falling behind for centuries. Systems are proposed, cover some data, only to become data that has to be covered by subsequent systems.

Some options to deal with this crisis:

  • Universal Logician/Ontologist Conscription Act – All 18 year olds world wide have to spend 6 years in the LogoOnto Corps. First four years learning the local flavor of linked data and the last two years coding data.
  • Excess data to /dev/null – Pipe all non-Linked data to /dev/null until logicians/ontologists can catch up. Projected to be sometime after 5500, perhaps late 5500′s. (According to Zager and Evans.)
  • ???

There are other options. Propose yours and/or wait for some suggestions here next week!

Posted in BigData, Linked Data, Logic, Ontology | 1 Comment »

New Opportunities for Connected Data (logic, contagion relationships and merging)

Thursday, January 26th, 2012

New Opportunities for Connected Data by Ian Robinson, Neo Technologies, Inc.

An in depth discussion of relational, NoSQL and graph database views of the world.

I must admit to being surprised when James Frazer’s Golden Bough came up in the presentation. It was used quite effectively as an illustration but I have learned to not expect humanities references or examples in CS presentations. This was a happy exception.

I agree with Ian that the relational world view remains extremely useful but also that it limits the data that can be represented and queried.

Complex relationships between entities simply don’t come up with relational databases because they aren’t easy (if possible) to represent.

I would take Ian’s point a step further and point out that logic, as in RDF and the Semantic Web, is a similar constraint.

Logic can be very useful in any number of areas, just like relational databases, but it only represents a very small slice of the world. A slice of the world that can be represented quite artificially without contradictions, omissions, inconsistencies, or any of the other issues that make logic systems fall over clutching their livers.

BTW, topic mappers need to take a look at timemark 34.26. The representation of the companies who employ workers and the “contagion” relationships. (You will have to watch the video to find out why I say “contagion.” It is worth the time.) Does that suggest to you that I could point topics to a common node based on their possession of some property, say a subject identifier? Such that when I traverse any of those topics I can go to the common node and produce a “merged” result if desired?

I say that because any topic could point to more than one common node, depending upon the world view of an author. That could be very interesting in terms of comparing how authors would merge topics.

Posted in Logic, Neo4j, NoSQL | No Comments »

Use Prefix Operators instead of Boolean Operators

Tuesday, January 24th, 2012

Use Prefix Operators instead of Boolean Operators by Chris Hostetter.

From the post:

I really dislike the so called “Boolean Operators” (“AND”, “OR”, and “NOT”) and generally discourage people from using them. It’s understandable that novice users may tend to think about the queries they want to run in those terms, but as you become more familiar with IR concepts in general, and what Solr specifically is capable of, I think it’s a good idea to try to “set aside childish things” and start thinking (and encouraging your users to think) in terms of the superior “Prefix Operators” (“+”, “-”).

Don’t hold back Chris! It’s not good for you. Tell us how you feel about “Boolean Operators.” ;-)

Seriously, Chris makes a very good case for using “Prefix Operators” and you will learn about powerful searching in both Lucene and Solr.

Well worth studying in detail.

Posted in Boolean Operators, Logic, Prefix Operators | No Comments »

A Description Logic Primer

Sunday, January 22nd, 2012

A Description Logic Primer by Markus Krötzsch, Frantisek Simancik and Ian Horrocks.

Abstract:

This paper provides a self-contained first introduction to description logics (DLs). The main concepts and features are explained with examples before syntax and semantics of the DL SROIQ are defined in detail. Additional sections review light-weight DL languages, discuss the relationship to the Web Ontology Language OWL and give pointers to further reading.

It’s an introduction to description logics but it is also a readable introduction to description logics (DLs). And it will give you a good overview of the area.

As the paper points out, DLs are older than their use with web ontology languages but that is the use that you are most likely to encounter.

You won’t find anything new information here but it may be a good refresher.

Posted in Description Logic, Logic, Ontology | No Comments »

Sharing and Integrating Ontologies

Monday, December 5th, 2011

Sharing and Integrating Ontologies

Peter Yim, organizer and promoter of all things ontological, reminded me of this effort quite recently.

If you were constrained by:

The semantics defined by ISO/IEC 24707 for Common Logic should be the basis for the logics used to define ontologies.

could you still write a topic map?

My suggestion would be yes, since a topic map is “without form and void” prior to being filled in by an author.

True, prior to doing that “filling in,” you will have selected a form to fill in, that is a data model (we call them legends) so your topic map already has some rules and topics in place before you start.

But, the fact remains you could write a topic map using the semantics of ISO/IEC 24707 and identify those semantics so that ontologies could be mapped to them.

Posted in Logic, Ontology | No Comments »

Data Integration: The Relational Logic Approach

Thursday, September 29th, 2011

Data Integration: The Relational Logic Approach by Michael Genesereth of Stanford University.

Abstract:

Data integration is a critical problem in our increasingly interconnected but inevitably heterogeneous world. There are numerous data sources available in organizational databases and on public information systems like the World Wide Web. Not surprisingly, the sources often use different vocabularies and different data structures, being created, as they are, by different people, at different times, for different purposes.

The goal of data integration is to provide programmatic and human users with integrated access to multiple, heterogeneous data sources, giving each user the illusion of a single, homogeneous database designed for his or her specific need. The good news is that, in many cases, the data integration process can be automated.

This book is an introduction to the problem of data integration and a rigorous account of one of the leading approaches to solving this problem, viz., the relational logic approach. Relational logic provides a theoretical framework for discussing data integration. Moreover, in many important cases, it provides algorithms for solving the problem in a computationally practical way. In many respects, relational logic does for data integration what relational algebra did for database theory several decades ago. A companion web site provides interactive demonstrations of the algorithms.

Interactive edition with working examples: http://logic.stanford.edu/dataintegration/. (As near as I can tell, the entire text. Although referred to as the “companion” website.)

When the author said Datalog, I thought of Lar Marius:

In our examples here and throughout the book, we encode relationships between and among schemas as rules in a language called Datalog. In many cases, the rules are expressed in a simple version of Datalog called Basic Datalog; in other cases, rules are written in more elaborate versions, viz., Functional Datalog and Disjunctive Datalog. In the following paragraphs, we look at Basic Datalog first, then Functional Datalog, and finally Disjunctive Datalog. The presentation here is casual; formal details are given in Chapter 2.

Bottom line is that the author advocates a master schema approach but you should read book for yourself. It makes a number of good points about data integration issues and the limitations of various techniques. Plus you may learn some Datalog along the way!

Posted in Data Integration, Logic | 1 Comment »

Philosophy of Language, Logic, and Linguistics – The Very Basics

Monday, September 19th, 2011

Philosophy of Language, Logic, and Linguistics – The Very Basics

Any starting reading list in this area is going to have its proponents and its detractors.

I would add to this list John Sowa’s “Knowledge representation : logical, philosophical, and computational foundations“. There is a website as well. Just be aware that John’s views on Charles Peirce represent a unique view of the development of logic in the 20th century. Still an excellent bibliography of materials for reading. And, as always, you should read the original texts for yourself. You may reach different conclusions from those reported by others.

Posted in Language, Linguistics, Logic | No Comments »

Introduction to Logic Programming with Clojure

Thursday, August 18th, 2011

Introduction to Logic Programming with Clojure

Assumes no background in logic but some experience with Clojure. A logic beginner’s tutorial.

Everyone has to start somewhere. Enjoy.

Posted in Clojure, Logic | No Comments »

Introduction to Logic Programming with Clojure

Monday, July 18th, 2011

Introduction to Logic Programming with Clojure

From the post:

How to use this Tutorial

This tutorial is meant to be used with a Clojure REPL handy. An example project has been set up.

You should be able to run all code examples in the logic-introduction.core namespace.

Won’t hurt you and could prove to be useful when having a go at logicians.

Posted in Clojure, Logic | No Comments »

The Haskell Road to Logic, Math and Programming [pdf]

Monday, January 3rd, 2011

The Haskell Road to Logic, Math and Programming [pdf] Authors: Kees Doets and Jan van Eijck

A detailed review can be found at: Book review “The Haskell Road to Logic, Maths and Programming” by Ralf Laemmel.

There are so many “cell phone dead zones” as Newcomb puts it when dealing with semantics that any assistance in clear thinking is welcome.

This is a work the promotes clear thinking.

Posted in Haskell, Logic | No Comments »

Common Logic, ISO/IEC 24707

Sunday, November 28th, 2010

Common Logic, ISO/IEC 24707

Every time I have a question about ISO/IEC 24707 I have to either find it on my hard drive or search for the publicly available text.

Don’t know that it will help to write it down here, but it might. ;-)

Questions (of course):

  1. Annotated bibliography of citation/use of ISO/IEC 24707. (within last year)
  2. Not a logic course but do you have a preference among the syntaxes? (discussion)
  3. Are ontologies necessarily logical?

Posted in Logic, Ontology | No Comments »