\usepackage[capitalize,noabbrev]{cleveref} \begin{lemma}\label{foo} Bar \end{lemma}then
\cref{foo}
gives Lemma x.y in the
PDF. Moreover, if we were to promote the lemma to a theorem,
then cref
automatically changes the references accordingly,
of course.
overfull hboxes
(in the bibliography, for instance).
mathtools
package\DeclarePairedDelimiter{\abs}{\lvert}{\rvert}allows you to write
\abs{x}
instead of
\lvert x \rvert
and even better,
\abs*{\frac{x}{y}}
\abs[\Big]{\frac{x}{y}}instead of
\left\lvert \frac{x}{y} \right\rvert
\Big\lvert \frac{x}{y} \Big\rvert.
\(...\)
for inline math\(...\)
rather than $...$
improves error messages. Besides, it makes more sense to have separate
opening and closing tags, just like you do for other LaTeX environments.