https://hackerpaper.kaipfister.de/p/0905.3010/Collected HN comments and submissions linking this paper.enMon, 02 Nov 2026 11:16:22 GMThttps://news.ycombinator.com/item?id=39987919urn:hackerpapers:mention:0905.3010:39987919Wed, 10 Apr 2024 07:25:07 GMT<p>A string diagram represents a computation using a monoid (associative binary operator with a common left/right unit element). You can interpret the computation as a dataflow through the inputs and outputs of the operators. By further characterizing members of the set, you can add constraints on the types (parts) of the data flow along edges. So they are just a monoid algebra, dressed up with category theory mumbo-jumbo: monoidal category. The origins go back to Einstein Summation Convention for writing products in vector/matrix/tensor math. Albert got fed-up with writing all the correct…</p><p><a href="https://hackerpaper.kaipfister.de/p/0905.3010/">Paper and discussion history</a>. A mention is not an endorsement.</p>quant-ph