Scaling down all the equations using one single command?

Question

I am about to submit an article with lots of equations in there (defined in both equation and align environments and I also have lots of inline math of course). There is a maximum page limit for the article and mine is quite above it. So, what I need to do is to scaling down all the equations to say 85% using minimum effort and edits to the text. Please note that I do not want inline math expressions to be affected by that macro, so that the text looks coherent at the end. Just wondering if a macro can be defined at the document preamble to do that for me?

Answer 1

I don't like the idea of reducing the font just for math expressions, but one option would be to use the etoolbox package and its \AtBeginEnvironment to change the font size for the displayed-math environments and \AfterEndEnvironment to restore the normal size; it's not a single command, but the number of environments for displayed math isn't too big. A little example:

\documentclass[conference]{IEEEtran}
\usepackage{bm}
\usepackage{amsmath}
\usepackage{mathrsfs}
\usepackage{upgreek}
\usepackage{etoolbox}
\usepackage{lipsum}

\AtBeginEnvironment{equation}{\par\footnotesize}
\AfterEndEnvironment{equation}{\normalsize}
\AtBeginEnvironment{align}{\par\footnotesize}
\AfterEndEnvironment{align}{\normalsize}
\AtBeginEnvironment{equation*}{\par\footnotesize}
\AfterEndEnvironment{equation*}{\normalsize}

\begin{document}
\lipsum[2] 
Utricularia, commonly and collectively called the
bladderworts, is a genus of carnivorous plants consisting of
approximately 233 species (precise counts differ based on
classification opinions; one recent publication lists 215 species).
They occur in fresh water and wet soil as terrestrial or aquatic
species across every continent except Antarctica. Utricularia are
cultivated for their flowers, which are often compared with those of
snapdragons and orchids, especially amongst carnivorous plant
enthusiasts.
\begin{equation}                                                                                                                                                                    
\bm{\tau}_{(\bm{\mu})}^\dagger = \lim_{j \to \infty} j.\bm{e}_{\upeta} - \mathscr{F}^{-1}_{1:\upeta} \left( \bm{\zeta}_j \right)                                                    
\end{equation}
\lipsum[4]
\[
a = b + c + d + e + f.
\]
\lipsum[4]
\begin{equation}
a = b + c + d + e + f.
\end{equation}
\lipsum[4]
\begin{align}
a &= b \\
  &= c \\
  &= d \\
  &= e \\
  &= f.
\end{align}

\end{document}

Without using additional packages, one can use some standard procedures such as

\let\oldequation\equation
\def\equation{%
  \footnotesize%
  \oldequation
}

or

\expandafter\def\expandafter\equation\expandafter{\equation\footnotesize}

but, the use of the etoolbox package makes the code shorter.