By the time he wrote to Engel on 23 May Killing had discovered that his conjecture about simple algebras was wrong, for he had discovered G, and by 18 October he had discovered the complete list of simple algebras.
Ng oras siya sa Engel wrote on 23 May pagpatay ay natuklasan na ang kanyang haka-haka tungkol sa mga simpleng algebras ay mali, para sa niya natuklasan G, at sa pamamagitan ng 18 Oktubre niya natuklasan ang kumpletong listahan ng mga simpleng algebras.