This
is obtained by
\begin{equation} f(z+h) -f(z) - h\times\mbox{RHS of \eqref{e14.27.11.16}} \end{equation}
but mediawiki does not support labels to equations, so texla outputs
<math display="block">f(z+h) -f(z) - h\times\mbox{RHS of \eqref{e14.27.11.16}}</math>
and mediawiki breaks