deletions | additions       diff --git a/section_Bytes_The_polynomials_in__.tex b/section_Bytes_The_polynomials_in__.tex  index 75d652e..4f9f38b 100644  --- a/section_Bytes_The_polynomials_in__.tex  +++ b/section_Bytes_The_polynomials_in__.tex 
...
\begin{itemize}  \item[i)] $A_1$ is an abelian group w.r.t. the sum of polynomials;   \item[ii)] $A_1\setminus\{0\}=\{1,x,x+1\}$ is an abelian group w.r.t. the product of polynomials;  \item[iii)] $(f+g)\cdot h=fh+gh$, for any $f,g,h \in A$. A_1$.  \end{itemize}  Since $A_1$ is formed by polynomials, properties i) and iii) are obvious.  As regards ii), we need only to prove that each nonzero element in $A_1$ has an inverse: