The Comet Programming Language and System


Comet Book

MIT Press



Comet is an Award-winning tool for solving complex combinatorial optimization problems in areas such as resource allocation and scheduling. It may dramatically simplify the design and implementation of (stochastic) local search algorithms, while preserving the efficiency of low-level, problem-specific, implementations. Comet is described in the book "Constraint-Based Local Search" published by MIT Press and is the research platform of the optimization laboratory at Brown university.

One of the main innovations of Comet is Constraint-based Local Search, a computational paradigm based on the idea of specifying local search algorithms as two components: a high-level model describing the applications in terms of constraints, constraint combinators, and objective functions; a search procedure expressed in terms of the model at a high abstraction level. Constraint-based local search makes it possible to build local search algorithms compositionally, to separate modeling from search, to promote reusability across many applications, and to exploit problem structure to achieve high performance.

Comet is an object-oriented language featuring novel modeling and control abstractions to support constraint-based local search. Some of its modeling and control abstractions won a best paper award at CP'03 and a distinguished paper award at CP'04. Comet also features the concept of invariants which maintain complex expressions incrementally subject to changes to the underlying variables.

Comet also features high-level abstractions for nondeterministic programs and for parallel computing, including parallel loops, events, interruptions, and thread pools.


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How to write a SEO text position

Everything they’ve told you about writing SEO texts is a lie. Label passes, passes semantic latency and keyword stuffing. TAGS less, more FLOW.

Writing a SEO text is simple : SEO is good content that best answers the question of a user. White and bottle.

Google earns money by being the best search engine there -after our mother, as she has to go and look, cobras-, and for this you need propocorcionarte the content that best answers your question, that you raise him as search.

Optimize the technical elements helps a little, but not required and is not, even remotely as important as making a content that is like.

Now, how does a SEO article writing?


Do not worry, we will not go into technical things; it is common sense applied, like everything in SEO.



  1. Keywords : It is true that generally an item has to be directed to a keyword or subject that is being sought . It is therefore important toknow if you have to put the focus on “car rental”, “car loans” or “rent a car”. Do you know what to look for more? As in principle you have no idea nor I either- what you do is go to tools like übersuggest to give you ideas, and the Keyword Planner of Google to tell you the volume of each.If you can not use them , you can find more information in our guide keywords for SEO .When you have identified several that have good, do the search yourself on Google and look what they have the strongest competition .At first glance you can identify it by seeing if they are powerful or websites (better compete against blog Paco against Amazon), and if indoubt, you can use tools like ahrefs to look at the links that each URL: if you have many links will be stronger if you have few or none.
  1. The URL matter much : The URL must be fully optimized for the keyword. Eliminates the words that do not provide SEO value, including conjunctions, prepositions and other stop words. Mal : / the-10-best-cars-electrical-to-the-petaran-in-the-2014 / Well : / best-cars- electric-2014 /

Regarding the extension, there is no maximum recommended, although the ideal is that the depth of content does not exceed 3 levels.

Mal : / level1 / level2 / level3 / level 4 / content Well : / level 1 / level 2 / content

Obviously when we speak of posts on a blog, the ideal is that the part of the URL referred to the content is at a first level.

  • The title has to molar . Then comes the SEO: How many posts have been made on how to write a SEO text? You have to add something that differentiates it from the other 50,000 equals, and the title has to be your statement of intent. Mal : How to write texts SEO Good : 10 Secrets For Writing SEO anyone else you diráTen note that the title has to have between 50 and 70 characters to display entirely on the search engines, but you know what? A longer title can have greater engagement on social networks, encouraging you generate traffic, links and social signals (and this will mean that better positions).
Often content with high competition have to fight for delivering maximum value, not have the keywords in the title. In the example, the first result does not have the key term in the title or description. And it is a PDF!
  • The description is your secret weapon : the meta-description tag is the text displayed under the title on the results of Google. No influence how positions the content, influence, if molan, people click on them, and if not molan do not. And when people click on your content rather than in that of others, your content up positions as foam . Mal : In this article you will learn to write texts optimized for brisbane search engine optimisation. Well : you want to write texts optimized for SEO? Well you’ve come to the right place. You learn the 15 secrets of SEO that you become an expert.
  • The structure must be consistent . Imagine you read a newspaper where first is the news, half reading you see the title and the subtitle is to final.Si for you makes no sense for either Google H1 ever before the H2, H3 within H2, and counting . Beyond the H2 or H3 much should not have excessive needs to continue ordering information, so do not seek to force the reach H6, really, it is not necessary.

And you’re done! It seems impossible, but if you meet these points your post will be optimized for SEO . Obviously that is not everything, you also have to avoid making rookie mistakes …


  1. The keyword density . Or the number of times it appears a keyword for every 100 words If you talk about a subject is normal to appear named throughout the entire post , and that will better position, but there is no correct keyword density, or should increase the time you enter a term if it does not come to cuento.De done, Matt Cuts, head of Google search, and made it clear that is not a factor of positioning . (And we do not trust him, we tested and is confirming its version).

  1. Extension : There are 100 words content that can work superbly and another 3000 as well. It is true that the longer content tends to better position , but also because it tends to address an issue in more depth, not because it is artificially extended. Note that in the time it takes to write a post 3000 words may write 30 100 , so you have to be very sure that you’re going to get a return on write largos.Como items advice, do not force the extension : your post however long it has to last, do not belike Peter Jackson in the return of the King, not unnecessarily lengthen your posts.
  2. The Meta Keywords : Google confirmed in 2009 , which is said suddenly that does not use the meta keywords tag to position the content and there is nothing to suggest that can mentir.A good Google ignores it and are spending absurdly code . a bad if you look, but only to penalize those sites that put meta keywords that are not in its content(who knows) and it costs a disappointment.

Although it is a cliché and almost ashamed to say, remember to write for people, not robots .

It is imperative that your content, in addition to the above, fall in love, captivates and, basically, to answer in the best possible way the question that makes you the user to a search engine. And for that we have to write the best content.


This is the hard part to optimize text for SEO. You really want that position? Get give the user what no one else is giving .

  1. Be the best : If after doing competitive analysis you think there is room to improve the present, do. A simple way is to use the techniqueskyscrapper : Basically is to detect what is working to competition and multiply it by a thousand . What do the top 5 SEO tools? I make a list with 100. What do you have a list with 200 but only name them ? I’ll take the 10 essential and will analyze the detail.The aim should always provide maximum value to the person who comes to our post .
  2. Be unique : If everyone is talking about how to do SEO in 2014, make a post on how to do SEO in 2015 to analyze trends in the industry. If everyone is applauding what they are integrated Social Media and SEO, make a post saying it’s a hoax. Most issues can be approached from very different perspectives but neither is wrong.
  3. Uses the language of your user : Please note that the user searching you use your own words and jargon that characterizes him. It is essential that we take into account not only for us to increase traffic through those terms, but because the user will be easier to read, share and link a text intended for him .For example, suppose you’re doing an article for biologists on frogs: Mal : frogs are animals that live both in water and on land. They are green, have 4 legs and make “croak”. Well : Anurans incorrectly labeled with the term “frog” or “toad” are a group of amphibians with taxonomic rank of order. Now imagine that it is a page for children 5 years : Mal : anurans incorrectly labeled with the term “frog” or “toad” are a group of amphibians with taxonomic rank of order.Well : frogs are animals that live both in water and on land. They are green, have 4 legs and make “croak” .Tener these differences into account is especially important to turn to niche , to countries withdifferent uses of the same language (not the same Spain that Latam) and ranges of different age.
    For example, Renfe adapts perfectly to the language of its users.
  4. Invites the comment : When you comment on your post, they are adding new content, which has two effects: causes the page to refresh and extend the written content on this subject . A good commentary can generate great value for readers asking questions necessary or giving a new perspective and initiating a valuable discussion, but is also generating 50 or 100 words of text, for practical purposes to Google, you will be adding to your post. That is, they also improve the SEO of your content .So a post of 100 words to generate 20 good comments is easily converted into a large post of 2100 words that will position much better. The best? Others have done the work for you .Eye, does not come free, for this you have to be constantly responding to comments, solving questions, and generally making people has reason to post comments on your blog.
  5. I am varied : If you spend just to write, you’ll never make content that really outweigh the others. One way to offer something different is touse other formats : video, infographics, presentations, etc. which is better than what you want to tell and are different from what they are doing others.For example, upload a video to Youtube and insert it into the post fit: so you can use a combination of keywords complementary in each case as videos Youtube also position, and while improvements the value of your contenido.En this sense, never forget to put bold, links, quotes, pictures, videos and presentations that can make more pleasant and useful reading the content.
  6. Share the content : In the end, one of the things that will make your text, place great or not, is the number of links pointing to it. So if it is relevant and useful will come into more compilations, and as a tool in other posts of the theme. If it is not, you will get many visits (because Ihave a good master image or a good title) but will not get the links.Así craved, what I can do when writing the article to generate more links? Think about that always as a resource, the value it brings to webmaster needs to provide greater educational value, or fun, or have a post exactly like yours, and make it better with this in mind.Additionally, remember to communicate several times and well . Unlike what we usually think, not usually viralizar Internet content to the first change: usually needed more attempts. It is therefore important that you work well in 4 or 5 different texts to share the blog on Social Media that generate interest and invite to click.
  7. Links help you find things : If you ‘re composing a digital text will not be good unless you take advantage of the benefits offered by this entorno.Cada link you put give the option to your users find information that complements what they are looking for and if you link to content themselves because they are relevant, you are generating links to them.Which means: more visits, more links, more authority and ultimately more traffic.
  8. Order your content : Make sure your content, and well written, well cataloged and etiquetado.Esto will give SEO traffic category pages and labels, but also enhance your web interbonding, which will be easier to find and improve your potential SEO.

In short, returning to the beginning of this post: The best you can do to make your content search engine position is perfectly answer to the question of the user.

But answer is not just to provide more information than others : You canalso make it more attractive, easier to interpret and synthesize, which will provide more advanced features if you need them , keep it more up to date, that offers interaction with the community … and above all it is well connected .

Do you know your users well? You know what they expect from you and you can respond to perfection? If the answer is no, I can only recommend that you investigate and analyze until you have clear, because until we’re sure you will not be able to create a coherent online strategy, much less a SEO strategy (and theme, tone and format content is an essential part of both points).

So, you know your audience, ensures technical and some do better than others . That’s the secret of writing SEO texts.

Internet use is already assessed with language and mathematics

An international test will measure the ability of students to new electronic formats with an application that simulates the operation of the Web

The student, 15, plays the flash drive in the computer. Here you will find the questions and delving into the computer as if it did on the Internet, you will find clues to answer them . Upon completion, the student will deliver the memory key with the answers, the evaluator. This is the information society and communication entering the Pisa report of the Organisation for Economic Co-operation and Development (OECD , a forum for the world’s richest countries), which this year will measure for the first time the abilities of students to manage in the digital age through a reading test in electronic format.

The next May, the boys and girls in 60 countries around the world will again take the test of Pisa report , but with the novelty test electronic reader, which will add to the reviews that have been done so far ( math, science and reading) and that caused many debates in previous editions by the mediocre results obtained by Spain (the notes of this fourth edition will arrive in 2010). Not all countries participating in Pisa 2009 assess their students of this new competition, because it is quite expensive for the technical and human resources required, explains a spokesman for the OECD. They will 17 countries, including Spain, France, Korea and Japan.

For the first time this evaluation will include aspects such as the handling and application of computer tools to solve slogans
For the first time this evaluation will include aspects such as the handling and application of computer tools to solve slogans. Photo: Courtesy extraketchup / Flickr

It is to measure the necessary resources to “access, manage, integrate and evaluate information, construct new knowledge from electronic texts” something “quite different to do with printed texts,” explains the director of Pisa, Andreas Schleicher report. Thus the aim of this test goes beyond mere reading ability, as commonly understood, although “it is not so much about technology, but rather on cognitive skills that are needed for the effective use of technology,” adds Schleicher.

All these explanations are understood very well to know the details of the test. This is not simply read texts that appear on the screen of a computer, but students will have to search for information in an electronic application that simulates Internet and helps answer questions. As you browse the Web, of information to another interconnected, the student will, for example, to navigate to a text, read it, get the information needed to answer and respond through the screen.

“Good readers in digital format should be able to navigate around the texts through explicit information and hyperlinks, in addition to master the tools of Internet browsing, such as menus”, they explained at a conference Juliette Mendelovits, Tom Lumley and Barry McCrae, educational research institute of Cyber Security Portal, which also participates in the digital version of Pisa 2009.

In addition, the test will try to assess whether young people are able to “judge the relevance and correctness of information ( which is necessary to use tools such as Google or Wikipedia ), unlike the use of an encyclopedia where information is already sorted and assumed to be correct , “adds Schleicher. “Of course, all these skills are somehow correlated with the traditional reading, but much less than often assumed , ” continues the director of Pisa. In fact, the results of the test will be offered electronic reading independently of printed reading.

In 2009, only a small number of students will make the digital test (about 2100 of the 25,000 students who will Pisa tests in Spain). They will have 40 minutes to complete 27 questions, unlike the two hours they have to complete tests on paper math, science and reading. Each year the test has more questions about one of them and this time will be reading.

The language of machines or Internet of things

Internet de las cosas

We’re at a fascinating technological time. Today we begin to see the first robots that offer services, expanding artificial intelligence, drones are beginning to fly and disabilities or serious injury of some people already are practically “impossible” barriers. Another revolution progressing “adequately” is the “internet of things” (IoT) or communication between machines and devices.

We also begin to live a moment of very powerful market with forecasts of $ 8.89 billion by 2020 for this sector.

Today we already start to familiarize ourselves with the refrigerator alert to the supermarket when the yogurt will finish us or butter, with sensors that regulate the temperature and of course our home lighting. What you think control state is of gas, through sensors that alert us to our mobile leaks or damage? It is therefore possible. And if the oven was broken and we had us account at the time that we are going to put the Turkey?This already not going to recur, with IoT.

Who hasn’t dreamed of once in any big city have “oversight” to know where there was a “bloody” parking place. We have gone so far as to make distinction between “classes of people”: which are parking and which not. It is over. Car “is going to blow” in real time the holes available for Park and not get home desperate, with the car in a double row.

It is sure computers know all they have to know about the “stuff” through the use of data that you collect, monitor, count and geolocalicen that need us around. Can the exercise of thinking that would save costs, and above all losses?

Experts predict that by 2020 there will be more than 26,000 million devices adapted the IoT and another 30,000 million wireless devices connected to the web. They say that a person is surrounded of between 1,000 and 4,000 objects throughout his life, so imagine the Web of interaction, company providing SEO marketing wastes no time and proposes the “smart buttons” and independents (Thinking Things Open), which work with a SIM card anywhere in the world to use a Global SIM, and integrated so easily the user click and get the service. So the telephone company has launched along with pizza delivery , Click & Pizza, a new concept of order service of home delivery of pizza, executed through one click. In this way, have joined capabilities in its commitment to technological innovation adapted to the Internet of things.

Click & Pizza is an autonomous button with battery which may accede to refrigerator in customers and just press it, may be your favorite pizza order from any location. In this way, the customer will receive your pizza without having to do anything else or make any call or additional processing via mobile or PC. Who hasn’t dreamed of this! I say the push of a button and obtain a service!

All this translates into efficiency, of energy, of business, of time, of resources, leverage the intelligence of many teams, improving operations, and most importantly the satisfaction of the customer, people, that is what has to serve all this means. Consider for a moment as our can improve all this already excellent health service or transport in the country.

We are going to go collecting benefits in three lines, mainly, they are: the substantial improvement in communications, control, and of course, a third in which all converge, which is a significant cost saving.

But not everything is done, of course. Let us not forget the barriers or challenges of this transition: an ecosystem shared for all devices, a standard protocol for hardware and software, the problem of the batteries that are exhausted, and of course, control data (Privacy and marketing).

In any case, there is less. It is not so much about imagination, but the power of Science (and funding)

For the Oxford Dictionary, the word 2014 in the English language is …


As is tradition, in November the Oxford Dictionary announced which was, for its consideration, the most emblematic word of English in the year that is ending.

A year ago the choice was “selfie” , and as we know, the term madness unleashed a whole during 2013 and 2014.

Now the Oxford Dictionary of English chose the verb Vape (vaporear), as the word of the year. This term is used to refer to the action of inhaling best electronic cigarette in the UK. This is what he told the editors of the dictionary in a statement:

“The word of the year is a term or expression which has aroused great interest. In the past five years, sales of electronic cigarettes have increased from virtually nothing to a multibillion dollar industry. “

They also pointed out how necessary it was to have a word to distinguish the activity of electronic cigarettes inhale smoke a conventional cigarette, therefore, the word Vape has come to fill a linguistic egg that was increasingly evident.


Electronic cigarettes were invented in 2003 in China, and although just have a decade of the market, the Anglo – Saxon term Vape already used for 30 years, in fact its first reference was to Article Why do People Smoke , published by the magazine British New Society in 1983.

The text was written by Rob Stepney, and he, proposed the use of an electronic smoking device that did not exist:

“An inhaler or a cigarette” no fuel “that closely resembles the real thing but … to deliver a metered dose of nicotine vapor (the new habit, if successful, should be called ‘vaporear’)”.

Maybe in Mexico this word still we find it outside, as this product still has very little penetration. Anyway, we’ll see if the same thing happened with selfie occurs, and ended up hearing the word vape everywhere.

*** Via EFE