Lambda Functions (fwd)

Max Hailperin max at max.mcs.gac.edu
Tue Aug 10 15:17:27 CEST 1999


xpolakis at hol.gr (Antreas P. Hatzipolakis) writes:

> ... Why lambda?  ...

We answer this question in the end-of-chapter notes for chapter 1 of
Concrete Abstractions(*), pp. 20-21.  The authority we cite there is
Barendregt(**).  In short, the story is that a circumflex (or "hat")
accent (^) that should have been over the top of the binding occurance
of the variable moved in front of it, and then by visual resemblence
the circumflex with nothing under it was turned into a greek letter
lambda.

That's the interesting part of the story, at least, from Church's
lambda calculi.  The later, less interesting part happened a couple
decades later when come Lisp (pre-Scheme), the greek letter had to get
spelled out in roman letters for the sake of primitive and
anglo-centric computer I/O devices.

(*)  Max Hailperin, Barbara Kaiser, and Karl Knight.  Concrete
     Abstractions: An Introduction to Computer Science Using Scheme.
     Brooks/Cole Publishing Company, 1999.

(**) Henk Barendregt.  "The impact of the lambda calculus in logic and
     computer science."  The Bulletin of Symbolic Logic, 3(2):181-215,
     June 1997.




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