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✨ Read this trending post from Hacker News 📖 📂 Category: ✅ Key idea: de Bruijn Numerals assumptions in this post understanding of pure lambda calculus zero-based de Bruijn indices instead of named variables nnn consecutive lambdas are written as λn\lambda^nλn ⟨n⟩e\langle n\rangle_e⟨n⟩e​ encodes n∈N0n\in\mathbb💬_0n∈N0​ as a lambda calculus term of encoding eee S(n)S(n)S(n) is the Peano successor function There are many ways to encode numbers and do arithmetic in the pure lambda calculus, for example using unary Church numerals, various nnn-ary representations, and the Scott encoding. A method that I have not seen yet is an encoding by reference…

💥 Discover this awesome post from Hacker News 📖 📂 Category: ✅ Main takeaway: Supply chain security is a hot topic today, but it is a very old problem. In October 1983, 40 years ago this week, Ken Thompson chose supply chain security as the topic for his Turing award lecture, although the specific term wasn’t used back then. (The field of computer science was still young and small enough that the ACM conference where Ken spoke was the “Annual Conference on Computers.”) Ken’s lecture was later published in Communications of the ACM under the title “Reflections on Trusting Trust.”…