The earliest instance I've seen to this equation, involving the Pauli matrices, is from a 1967 paper by J. M. Levy-Leblond. But it seems general and useful enough that it must have been discovered earlier:(adsbygoogle = window.adsbygoogle || []).push({});

[itex](\sigma \cdot A)(\sigma \cdot B) = A \cdot B + i \sigma \cdot (A \times B)[/itex]

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# Who developed this equation, Pauli?

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