Borrowing from @Frost's review on Penrose, Euler is the one of the three mathematician breakers in the Ashes cycle. Euler is often known for Euler's Method, a procedure for solving differential equations in calculus. The other breaker in the cycle is Gauss.

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My links were set up incorrectly, other than to Euler's Method. Penrose, Euler, and Gauss linked correctly here.