deletions | additions       diff --git a/bits3.tex b/bits3.tex  index dae718f..b37f080 100644  --- a/bits3.tex  +++ b/bits3.tex 
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comments.  \end{Exercise}  Let us consider the vector $(0,1,1)\in (\Fb)^3$, associated to the polynomial $f(x)=x^3+x+1$ as explained above. We point out that this polynomial is irreducible.  We  can construct a Linear Feedback Shift Register (LFSR) over three bits, using $f(x)=x^3+x+1$. \\  First of all, we start with an initial vector called \emph{state}, for example $(1,0,1)$, inserting it in the following structure: 
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Now, we shift the vector to the right:  \begin{center}  \begin{tabular}{ |c || c | c | c } |}  \hline  ?&1 & 1 & 0 \\  \hline  \end{tabular}  \end{center}  so we have a new state and we can repeat the algorithm. algorithm:  \begin{center}  \begin{tabular}{ |c || c | c | c |}  \hline  1&1 & 1 & 0 \\  \hline  \end{tabular}  \end{center}  getting  \begin{center}  \begin{tabular}{ |c || c | c | c |}  \hline  ?&1 & 1 & 1 \\  \hline  \end{tabular}  \end{center}  We repeat again  \begin{center}  \begin{tabular}{ |c || c | c | c |}  \hline  0&1 & 1 & 1 \\  \hline  \end{tabular}  \end{center}  getting  \begin{center}  \begin{tabular}{ |c || c | c | c |}  \hline  ?&0 & 1 & 1 \\  \hline  \end{tabular}  \end{center}