Added the unitisation.

src/op/banach/gelfand.tex

@@ -19,7 +19,6 @@
 \label{proposition:gelfand-transform-gymnastics}
     Let $A$ be a commutative unital Banach algebra and $x \in A$, then:
     \begin{enumerate}
-        \item $\Gamma_A$ is a contractive homomorphism. 
         \item $\Gamma_A(1) = 1$. 
         \item $x \in G(A)$ if and only if $\Gamma_A x \in G(C(\Omega(A); \complex))$. 
         \item $(\Gamma_Ax)(\Omega(A)) = \sigma_A(x)$.