Understanding Lambda Calculus and Its Role in Computer Science

In summary, the conversation is about lambda calculus, which is used in computer science as an alternative to Turing machines. The person asking the question is unsure about how to interpret a variable in a lambda expression and is seeking clarification. Another person responds, stating that they are not familiar with lambda calculus and suggests waiting for a more experienced person to answer.
  • #1
hant
1
0
Hello, I have a simple question.
When reducing a lambda expression what happens in this case:

(L x.y) (L z.z) (L z.z) -> y (L z.z) right?

How to interpret the variable y in front? Is that normal form, or can
I reduce it to just: y
Or is the expression ilegal?
Thanks
 
Physics news on Phys.org
  • #2
At the risk of being flamed, I'm a pretty experienced mathematician, and I' have no idea what you mean by any of those expressions. I'm not going to say they are non-standard, but I think you ought to at least indicate what they mean if you want an answer.
 
  • #3
matt grime said:
At the risk of being flamed, I'm a pretty experienced mathematician, and I' have no idea what you mean by any of those expressions. I'm not going to say they are non-standard, but I think you ought to at least indicate what they mean if you want an answer.

It's Lambda Calculus. It's used in computer science as an alternative to Turing machines; instead of representing computation as the operation of a machine, we represent it as the evaluation of functions. Unless you've specifically studied computer science it's unlikely you would have ever even heard of it.

I would try and help, but I'm only an undergraduate; one who hasn't had any formal lectures involving lambda calculus. If you don't mind waiting a year I can get back to you... :biggrin:
 

What is normal form in Lambda calculus?

Normal form is a form of expression in Lambda calculus where no further reduction can be performed. It is the most simplified form of an expression and is achieved by applying reduction rules until no further reductions are possible.

What is the difference between normal form and weak normal form in Lambda calculus?

Normal form is the most simplified form of an expression in Lambda calculus, while weak normal form is a form of expression where only the outermost reduction has been performed. This means that there may still be sub-expressions that can be reduced in weak normal form.

How do you convert an expression to normal form in Lambda calculus?

To convert an expression to normal form in Lambda calculus, you need to apply reduction rules until no further reductions can be made. This can be done manually by following the reduction rules or by using a computer program or interpreter.

What is the purpose of normal form in Lambda calculus?

The purpose of normal form in Lambda calculus is to simplify expressions and make them easier to analyze. It also allows for easier comparison of different expressions and makes it possible to prove the correctness of a program or function.

Can all expressions in Lambda calculus be reduced to normal form?

No, not all expressions in Lambda calculus can be reduced to normal form. For example, recursive functions may not have a normal form. However, for most expressions, normal form can be achieved by applying reduction rules.

Similar threads

Replies
26
Views
1K
Replies
1
Views
904
  • Advanced Physics Homework Help
Replies
4
Views
2K
Replies
2
Views
1K
  • Set Theory, Logic, Probability, Statistics
Replies
8
Views
1K
Replies
1
Views
1K
  • Differential Equations
Replies
1
Views
2K
  • Other Physics Topics
Replies
1
Views
2K
  • Calculus
2
Replies
38
Views
5K
Back
Top