ho boon suan

currently i am playing the role of undergrad at the national university of singapore (NUS) — you can reach me at hbs@u.nus.edu!

some friends: timo, wyan

i write stuff and put it on the internet sometimes:

• A generalization of Boppana's entropy inequality, submitted (2026) (formalized in Lean!)
• Two product formulas for counting successive vertex orderings, arXiv preprint (2023)
• Equality cases for a bound on the chromatic number, with Joel Tan Junyao and Zhang Xiaorui, arXiv preprint (2019)


• a cute set of balanced Masyu puzzles i made with my friend gabriel (The Art of Computer ProgrammingTAOCP volume 4B, exercise 7.2.2.1–425)
• a Manim animation of a universal graph that contains every four-vertex graph as an induced subgraph (TAOCP volume 4C, exercise 7.2.2.3–212)


• some solutions to Tao's UCLA course 245A Measure Theory (2021, 44 pages)
• some solutions to Tao's 245B Real Analysis (2022, 78 pages)
• some solutions to chapter 1 of Yufei Zhao's 2023 book Graph Theory and Additive Combinatorics


• expository note: The Cauchy–Binet formula (2021, 3 pages)
• expository note: Two non-attacking queens (2022, 1 page)
• a note on exercise 3.2.1.1–3 of The Art of Computer Programming (17 Jul 2025)


• tiny animation of a Dyck cycle
• Mathematica notebook that supplements my paper "Two product formulas…" (2023)
• slides from a talk at the NUS combinatorics and graph theory seminar: How many ways are there to traverse a graph? (09 Oct 2024)

some books that i love: Rainer Maria Rilke, Letters to a Young Poet (1903–1908); Jeffrey Kripal, The Flip (2019); Iain McGilchrist, The Matter with Things (2021); Bernardo Kastrup, The Daimon and the Soul of the West (2025); Paul Kingsnorth, Against the Machine (2025)