Compile twice. Result: Equation (1) has a number, equation (2) has no number. autonum is a powerful, time-saving package for authors who want their equation numbering to be driven by content references rather than manual decisions. It integrates seamlessly with standard math environments and reference packages, making it an excellent choice for technical documents of any length. The only requirement is a habit of compiling twice (or using latexmk ) – a small price for fully automated numbering hygiene. Further information : Full documentation is available on autonum.info or by running texdoc autonum in your TeX distribution.
\beginalign x &= y + z \labeleq:first \ a &= b - c \labeleq:second \endalign
\usepackageautonum \documentclassarticle \usepackageamsmath \usepackageautonum \begindocument
We only refer to \eqrefeq:first. Hence only the first line gets a number.
% This equation will NOT be numbered (no reference) \beginequation a^2 + b^2 = c^2 \endequation
autonum is often preferred over mathtools ’ showonlyrefs because autonum works with more environments and handles \label placement more robustly. \documentclassarticle \usepackageamsmath \usepackage[colorlinks]hyperref \usepackagecleveref \usepackageautonum \begindocument
\enddocument
1. Overview The autonum package (found at autonum.info ) provides a sophisticated solution for managing equation numbering in LaTeX documents. Its core purpose is to automatically control which equations receive numbers based on whether they are referenced elsewhere in the text.
\beginequation f(x) = x^2 \labeleq:square \endequation
% This equation will be numbered because it is referenced below \beginequation E = mc^2 \labeleq:einstein \endequation