Tuesday, September 26, 2017

September 26, 2017 Tuesday

Bedtime Story 


A Set of Postulates for the Foundation of Logic 1932


As mon ami says, in the name of atheism I was carrying out my own jihad on disbelief which in a way is no different from any other religion.

So let us leave aside the religious beliefs of Church and return back to our primary theme of the story, which is the Entscheidungsproblem and the contribution of Alonzo Church to it.

Church too began to ponder over the problem that Hilbert and Ackermann had posed: Is there a decision procedure to determine if any particular statement of first-order logic is true or false?

Church too was interested in the foundations of mathematics.

In 1932 Church published a paper in the journal Annals of Mathematics titled “A set of postulates for the foundation of logic”.

He republished this paper in 1933 with further refinements.

It was in these papers that Church first introduced lambda-calculus or λ-calculus.   

You might think from the name that this lambda calculus must be that formidable calculus that so scared you in high school or maybe even worse than calculus since it has that dreadful lambda added along to calculus.

You will be surprised to know that the calculus of Church has nothing to do with mathematical analysis that involves differentiation and integration.

What is common to both the calculi though is the notion of functions albeit considered in totally different ways.

I discussed a lot about functions in my previous bedtime stories.

The function that Church was dealing with is specifically known as computable function.

Computable function has a direct bearing on the problem that was posed by Hilbert and Ackermann.

And on the other side, computable functions have a deep-seated link with algorithm that in the modern world forms the basis of computer programming.

Computable functions are formalized analog of the intuitive notion of algorithm that we all very familiar with even if we have never been programmers in any serious sense.

To put it most simply, a function is computable if there is an algorithm for it.

Or in other words, if there is a certain input, using certain finite number of steps, its output can be worked out for that function.

Let me try to explain lambda calculus in as simple way as it is possible.

I am no computer scientist without any formal training either in mathematics, or in formal logic or in computer science.

Whatever little I do know on these subjects is largely inspired by mon ami’s fascination for these subjects and my fascination for his fascination.

Stay tuned to the voice of an average story storytelling chimpanzee or login at http://panarrans.blogspot.com
                              
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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