Panini's Grammer

While reading the chapter on "A Simple One-Pass Compiler" in the Book "Compilers: Principles, Techniques and Tools", I came across the following sentence mentioned in the bibliography section.

Context-free grammars were introduced by Chomsky [1956] as part of a natural languages. Their use in specifying the syntax of programming languages arose independently. While working with a draft of Algol 60, John Backus, "hastily adapted [Emil Post's productions[ to that use" (Wexelblat [1981, p.162]). The resulting notation was a variant of context-free grammar. The scholar panin devised an equivalent syntactic notation to specify the rules of Sanskrit grammar between 400 B.C and 200 B.C (Ingerman [1967])

There is a section in the wikipedia on Panini's influence on Modern Linguistics.

Chomsky, during his visit to India and had an humble acknowledgment for generative grammar devised by Panini.. "happy to receive the honour in the land where his subject had its origin. "The first generative grammar in the modern sense was Panini's grammar","

G Cardona, Panini : a survey of research (Paris, 1976), quotes

Panini's grammar has been evaluated from various points of view. After all these different evaluations, I think that the grammar merits asserting ... that it is one of the greatest monuments of human intelligence.

There was a debate brought about on Ingerman's suggestion to name Backus-Naur Form has Panini-Backus form and author, who has studied both Panini's Asthadhyayi and BNF states that both are quite different.

The main point is that Panini's system of codes, abbreviations, and

redefined case endings is vastly more subtle and sophisticated than BNF,

and is aimed at doing a different job. BNF is really just a very simple

way of writing down the logical relationships between items in a program; a

linear version of Venn diagrams, almost. It is purely descriptive, where

as Panini's rules are operative. To put it differently, BNF notation is

useful for describing grammars; the Astadhyayi is a grammar.

Discussion link

Based on these references, I can see that Panini's was a definitive grammar for the Sanskrit language and can be regarded as scholarly approach to devise a system for the representation of the language. In days when we don't find any of his contemporaries making such attempt or even linguists for a hundreds of years to come.

About Ramanujan

I was looking for some information on Srinivasa Ramanujan, that I stumbled upon this post at y! answers.

Mathematician Ramanujan. The greatest ever.

Born 22 December 1887(1887-12-22)

Erode, Tamil Nadu, India

Died 26 April 1920 (aged 32)

Chetput, (Madras), Tamil Nadu, India

Residence

British India,

United Kingdom

Fields Mathematician

Alma mater

Trinity College, Cambridge

Academic advisors G. H. Hardy and J. E. Littlewood

Known for Landau-Ramanujan constant

Mock theta functions

Ramanujan prime

Ramanujan-Soldner constant

Ramanujan theta function

Ramanujan's sum

Rogers-Ramanujan identities

Ramanujan and his theorems are referred to in Sylvia Nasar's A Beautiful Mind, a biography of mathematician John Forbes Nash.

He is the subject of David Leavitt's new novel The Indian Clerk, released September 2007. The novel is set during Ramanujan's sojourn in England, where he went at the invitation of Cambridge mathematician G.H. Hardy and his colleague J.E. Littlewood.

He was referred to in the film Good Will Hunting as an example of mathematical genius.

His biography was highlighted in the Vernor Vinge book The Peace War as well as Douglas Hofstadter's Gödel, Escher, Bach.

The character Amita Ramanujan in the CBS TV series Numb3rs (2005–) was named after him.[90]

The short story "Gomez", by Cyril Kornbluth, mentions Ramanujan by name as a comparison to its title character, another self-taught mathematical genius.

In the novel Uncle Petros and Goldbach's Conjecture by Apostolos Doxiadis, Ramanujan is one of the characters.

In the novel Earth by David Brin, the character Jen Wolling uses a representation of Sri Ramanujan as her computer interface.

In the novel The Peace War by Vernor Vinge, a young mathematical genius is referred to as "my little Ramanujan" accidentally. Then it is hoped the young man doesn't get the connection because, like Ramanujan, the boy is doomed to die prematurely.

The character "Yugo Amaryl" in Isaac Asimov's Prelude to Foundation is based on Ramanujan.[citation needed]

The theatre company Complicite has created a production based around the life of Ramanjuan called A Disappearing Number - conceived and directed by Simon McBurney

The PBS television show Nova episode "The Man Who Loved Numbers", about Ramanujan, was first broadcast on March 22, 1988.

The Helix comic book series Time Breakers features Ramanujan as a character. In the story, his meeting with Hardy was made possible by the time travelling main characters, who know that Ramanujan's discoveries are vitally important to their own work and ensure that his work at Cambridge will unfold as history demands.

The eponymous character in J.M.Coetzee's novel 'Elizabeth Costello: Eight Lessons' uses Ramanujan to discuss God, reason and being human.

Good Will Hunting

At last my desktop computer running FC2 was able to play movies from VCD. VLC did the trick and I had to spend considerable time with it to make it play.

1) vlc vcd:///dev/hdc

2) next to scroll bar there was chapter button. Click on that so that it does not finish with the advertisements only.

Good Will Hunting was an 'okay' movie.  It was trying to be a sentimental, emotional one. But there were lots of loop holes. Well movies as such have lots, but this was a little extra special in terms of mathematical genius janitor who is an autodidactic and considers himself correct all the times. Robin Williams plays the psychologist part and tries to help him find his way. Which you can expect in a movie, would be to get back to his heroine with whom he had a break-up. Thats following his heart.

I liked the slangs used, the boston country side and bars potrayed and the joke the heroine shares in bar with friends.  :-)

J.K. Rowling on failure, imagination and life

A very good speech given by J.K. Rowling to the students of Havard. This reminds of the famous Steve Jobs speech too. But there is something observable in J.K.Rowling's concluding part. It is same that Harry says to Hermoine in the "Order of the Phoenix" as the answer to the question, "What do we have that the dark lord voldemort does not and envies?"

How identation works for Python programs?

It is well explained in this article.

It is the lexical analyzer that takes care of the indentation and not the python parser. Lexical analyzer maintains a stack for the indentation.
1) First for no indentation, it would stored 0 in the stack [0]
2) Next when any Indentation occurs, it denotes it by token INDENT and pushes the indent value to the stack[0]. Think of it as a beinging { brace in the C program. And if we visualized, the can be only one INDENT statement per line.
4) When de-indent occurs in a line, as many values are popped out of the stack as the new reduced indentation till the value on the top of the stack is equal to new indentation (if not equal, error) and for each value popped out a DEDENT token in written. (Like multiple end }} in C)

A simple code like this



if x:
if true:
print 'yes'
print 'end'


Would be written as:

<if><x><:>                           # Stack[0]
<INDENT><if><true><:>  # Stack [0,4]
<INDENT><print><'><yes><'> # Stack [0,4,8]
<DEDENT><DEDENT><print><'><end><'> #Stack[0]

The parser would just consider the as <INDENT> as { of the block and  <DEDENT>  as } of the block would be able to parse it as logical blocks.

That was a well written article again.

Maharishi Mahesh Yogi died last week.

Maharishi Mahesh Yogi, was the guru of Transcendental Meditation technique. There are many different meditation techniques in the world. Meditation is a concept for your thoughts, which is similar physical exercise is for body.

Transcendental Meditation is one of them and Maharishi Mahesh Yogi pioneered it. I learned it when I was in 10th standard,16 years old and practiced it till my first year at job when I was in tech-support department at Dell, 23 years old. I feel, I had started meditation, because I wanted to improve my marks and achieve big things :-) and pursued it for 7 years intermittently, constantly getting confused with many things, without achieving the purpose of marks and big things. During this time, the Meditation activity also took me into religion and other spiritual activities in the related sphere and I got easily influenced by them also. My interests included, Sri Ramakrishna Mutt, Swami Vivekananda, Osho, temples and various different philosophical reading.

It was when doing night-shifts at work that I did not get time for these and because during the day time with whatever time I got, I wanted to study and prepare for a move to software development that my interests in meditation started to fade away. I think, being in Bangalore than in Madurai (where you have lot of temples and average interest in spiritual things is very high) and away from some friends who had shared my previous interests also led to this change. I was also disgusted with wrong paths which people might follow, if they just pray to god and not do the required work in trying to achieve what they wanted. So many nearby examples and sometimes myself included were in my mind. So, I simply kind of gave it up.

Our interests change at different points in time. Right now, I do physical exercises everyday, enjoy it without any aim for marks or achieving big things.

When thinking about the subject of meditation sometimes, I feel that it can be equated to exercises for your thoughts and it should not be a heavy subject however and should definitely not be linked with many things.

There are lots of article on Mahesh Yogi, Beatles involvement and Mahesh Yogi's achievements in field of meditation under the entertainment section of the news today.

Remembering Mahatma

Whether we follow or not, Mahatma Gandhi's philosophy is as relevant today as it was 60 years ago.

I went to a hotel called Rasam at Chennai along with my cousin. It was a Kongunadu style,the karaikudi area in Tamil Nadu and it had a display of historic newspaper clippings. One newspaper clipping was on Indian Independence and titles ran large with details and the photos of the ministers sworn in.

There was a small column however there that Mahatma Gandhi was in a village where in he was helping the riot affected people and he observed Independence Day by fasting, spinning, prayer. This is truly inspirational of a great leader.Dr. Kalaam also mentions about this incident in his books.

Quote of the day:

"Whatever we do might be insignificant, but it is very important that we do it" - Gandhi