# Lambda Calculus - Evaluating Expressions #4

madspbuch + 0 comments Yep, These questions are pointless. Without the knowledge that we are talking about church numerals, it is just combinators.

exfalso + 0 comments These questions are so pointless, they put off people who aren't familiar with church encodings, and piss off people who are. Booo

scott_sedgwick + 1 comment Hi alexkorotkikh,

I don't pretend to deeply understand this, but basically all those things were Church numerals.

IIRC, there is a chapter devoted to them in SICP too.

Scott.

alexkorotkikh + 0 comments Thanks a lot, Scott! Will check and try again :)

alexkorotkikh + 1 comment I'm not very good in lambda calculus :( can somebody point me to some resources I can read and understand how result can be integer if there's no numeric input for lambda expression.

madspbuch + 0 comments Look up church numerals :-) (as stated otherwise in this thread, the questions are pointless without this piece of intermation.)

peterb3 + 0 comments The answer is "2", and this is an absolutely terrible series of problems that barely explains why anyone should care. Even knowing what I know about Church numerals I feel that all these questions are doing is irritating the user.

- MD
dMike + 0 comments I've made it this far, put the correct answers in the box, but I have no idea what I'm doing :/

- SP
sughan100 + 1 comment lamda X.lamda Y.X(X(Y))=2

Akeempositive + 2 comments Can you explain, please?

- JS
zhiwangshi28 + 0 comments 0 = Î»f.Î»x.x

1 = Î»f.Î»x.f x

2 = Î»f.Î»x.f (f x)

in this problem, replace f with x and x with y

- MK
khairul + 0 comments The way I think of church numerals is as follows. 0 is defined as just your input so x 1 is defined as applying a generic function once to your generic input so f(x) 2 is f(f(x)) and so on. In lambda calculus this 2 would be expressed as Î»f.Î»x.f f x.

No more comments

Sort 8 Discussions, By:

Please Login in order to post a comment