[Haskell-cafe] why the name lambda calculus?

Tony Finch dot at dotat.at
Mon Aug 22 17:09:34 CEST 2011

KC <kc1956 at gmail.com> wrote:
> Lambda abstraction was probably chosen in case someone found better
> abstractions; e.g. epsilon, delta, gamma, beta, alpha, ... :)


Page 7:

By the way, why did Church choose the notation "λ"? In [an unpublished
letter to Harald Dickson, Church] stated clearly that it came from the
notation "x̂" used for class-abstraction by Whitehead and Russell, by first
modifying "x̂" to "∧ x" to distinguish functionabstraction from
class-abstraction, and then changing "∧ " to "λ" for ease of printing.
This origin was also reported in [Rosser. Highlights of the history of the
lambda calculus. Annals of the History of Computing]. On the other hand,
in his later years Church told two enquirers that the choice was more
accidental: a symbol was needed and "λ" just happened to be chosen.)

f.anthony.n.finch  <dot at dotat.at>  http://dotat.at/
Tyne, Dogger: Northwest becoming variable then east, 3 or 4, increasing 5 or 6
later. Slight or moderate. Showers, thundery later. Moderate or good.

More information about the Haskell-Cafe mailing list