Monday, May 22, 2017

May 22, 2017 Monday

Bedtime Story   


Understanding 'Lexicographical Order' and 'Canonical' in Richard's Paradox


We will need to digress once again a wee bit to understand this new terminology ‘lexicographical order’.

The word lexicographical is derived from the word lexicon that in turn is derived from a similar Greek word meaning “of or for words”.

So what exactly is a lexicon?

The guys who study natural languages (as opposed to programming languages) are called linguists.

According to top linguists, our language essentially consist of two components, its lexicon or the collection of words (its wordstock) and its grammar, the system of rules that determines the rules of their combination to form meaningful sentences.

Lexicographical order is also referred to as dictionary order or alphabetical order.

It came as a surprise to me that this terminology is as much a mathematical term as much as it is used in linguistics.

In mathematics, it is a terminology that belongs to set theory.

While specifically it signifies arrangement in alphabetical order, in a more generalized sense it pertains to the arrangement of elements in a finite totally ordered sets.

So if there exists a total order in the arrangement of elements of a finite set, that would be called a lexicographical order.

Returning back to our Richard’s paradox, when you arrange the sentences that precisely define real numbers first length-wise and then lexicographically, the form of arrangement that you get is called canonical.

Canonical form is just a technical term in mathematics to state that something now has a mathematical expression.

Canonical is simple English refers to any object that has been sanctioned or authorized by some supreme governing body.

So now having achieved this canonical form of arrangement, we would have a list of infinite sentences describing a specific real number arranged in a specific manner.

To get it straight, a definition that has lesser number of letters will precede the one that has more number of letters.

Further, if it happens that two definitions have the same number of letters, then alphabetical order will determine their placement. 

Having done so, Jules Richard asks you to define a new real number r as follows:

The integer part of r is zero, the nth decimal place of r is 1 if the nth decimal place of rn is not 1, and the nth decimal place of r is 2 if the nth decimal place of rn is 1.

Here rn designates any possible real number 

Please note that in statement we are constructing a new real number r that is different from any other rn in a very specific manner. 

Now all you have to do is glance back at the two statements of English language that we created to define real numbers.

I pray mon ami, go over this last part again and again and let it sink in.

We shall go over it again to fully comprehend its construction and ramification.

Stay tuned to the voice of an average story storytelling chimpanzee or login at http://panarrans.blogspot.in/
                              
Good night mon ami and my fellow cousin ape.
                           
  
                

             












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Another great educator and a teacher that I am aware of is Professor Subhashish Chattopadhyay in Bangalore, India.

While I narrate stories, Professor Subhashish an electronic engineer and a former professor at BARC, does and teaches real mathematics and physics.

He started the participation of Indian students at the International Physics Olympiad.

Do visit him here:


All his books can be downloaded for free through this link:


For edutainment and English education of your children, I recommend this large collection of Halloween Songs for Kids:

https://www.youtube.com/channel/UCd14DRdYKj454znayUIfcAg

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