TITLE: Why is lambda calculus named after that specific Greek letter? Why not “rho calculus”, for example?
QUESTION [44 upvotes]: Where does the choice of the Greek letter $\lambda$ in the name of “lambda calculus” come from? Why isn't it, for example, “rho calculus”?

REPLY [7 votes]: Dana Scott, who was a PhD student of Church, addressed this question. He said that, in Church's words, the reasoning was "eeny, meeny, miny, moe" — in other words, an arbitrary choice for no reason. He specifically debunked Barendregt's version in a recent talk at the University of Birmingham.

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