A common myth in theoretical computer science is that the ‘λ’ in λ-calculus comes from some kind of typographical error, where the intended notation was a circumflex accent *ŷ.M*, which became a caret* ^y.M *then finally a lambda *λy.M*. At least on the math stack-exchange this is the most popular explanation [link].

We recently had λ-calculus pioneer Prof. Dana Scott give a series of lectures in our School. He was a PhD student of Alonzo Church. In the introduction of one of his lectures he told us the story of the Greek letters used in the λ-calculus: the α of α-conversion, the β of β-expansion, the η of η-expansion and of course λ itself.

He says that when Church was asked what the meaning of the λ was, he just replied “*Eeny, meeny, miny, moe.*“, which can only mean one thing. It was a random, meaningless choice. Prof. Scott claimed that the typographical origin myth was mainly propagated by Henk Barendregt and is just pure whimsy. He asked us to stop perpetrating this silly story.

I am attaching the link to the YouTube video with apologies for the low quality.

## About Dan Ghica

Reader in Semantics of Programming Languages //
University of Birmingham //
https://twitter.com/danghica //
https://www.facebook.com/dan.ghica