diff --git a/src/op/banach/multiplicative.tex b/src/op/banach/multiplicative.tex index 350fa62..25e94fa 100644 --- a/src/op/banach/multiplicative.tex +++ b/src/op/banach/multiplicative.tex @@ -97,12 +97,12 @@ &= 2[x(yxy) + y(xyx)] \in \ker \phi \end{align*} - and $(xy - yx)^2 \in \ker\phi$ as well, and + and $(xy - yx)^2 \in \ker\phi$. Since \[ (\phi(xy - yx))^2 = \phi((xy - yx)^2) = 0 \] - Therefore $2xy = (xy + yx) - (xy - yx) \in \ker \phi$, $\ker \phi$ is an ideal, and $\phi$ is a homomorphism. + The commutator $xy - yx \in \ker \phi$ as well. Therefore $2xy = (xy + yx) - (xy - yx) \in \ker \phi$, $\ker \phi$ is an ideal, and $\phi$ is a homomorphism. \end{proof}