deletions | additions       diff --git a/subsection_applying_information_theory_to__.tex b/subsection_applying_information_theory_to__.tex  index 427f005..8ac9c08 100644  --- a/subsection_applying_information_theory_to__.tex  +++ b/subsection_applying_information_theory_to__.tex 
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If we make the linearising assumption that the total change in pressure and velocity is equal to the sum of the forward and backward changes  \[  dP = dP_+ + dP_- \qquad \mbox{and} {and}  \qquad dU = dU_+ + dU_- \]  then we can solve for the forward and backward pressure changes in terms of the measured changes $dP$ and $dU$  \[