## help with [Barendregt & Barendsen, 1994]

I'm working my way through An Introduction to Lambda Calculus (Barendregt & Barendsen, 1994) and I was wondering if there is an answer sheet available, or a forum where I could talk with someone about the problems in the text. In particular, problem 2.11

Show

∀ C[, ] ∃ F ∀ x Fx = C[F, x]

and take another look at the exercizes 2.8, 2.9 and 2.10


has me stumped. I don't understand the bracketing convention used following C, and I don't get what's so special about the result shown in this exercize.

## Comment viewing options

### it's not homework...

Really. I'm not even a student - I work as a sysadmin for a small firm in the Bay Area.

### This is an instance of the

This is an instance of the convention at the end of section one -- M[x] is a term with x free in it, and M[x,y] is a term with both x and y free in it. See the bottom of page 10 where he defines the vector notation for free variables.