Alonzo and Lambda
Alonzo Church was an American mathematician and logician who made major contributions to mathematical logic and the foundations of theoretical computer science. He is best known for the lambda calculus, Church–Turing thesis, proving the undecidability of the Entscheidungsproblem, Frege–Church ontology, and the Church–Rosser theorem. He also worked on philosophy of language.
Drawn from photo as reference, with Pentel ink brush.
Used as background in the r/functionalprogramming subreddit community.
Later used by a PhD student in his thesis presentation for a French university.