deletions | additions       diff --git a/Investigation.tex b/Investigation.tex  index 0f942ee..3ccda27 100644  --- a/Investigation.tex  +++ b/Investigation.tex 
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(d|0;n);m =(d;m)|(0;n), \;\; d\in[0,9]  \end{equation} For the pipe and semi-comma operations we have identity \begin{equation}  0|a = a \\  a;1 = a \\  a;0 = 1 or 1???  \end{equation}