I was recently required by a journal to getting rid of \def in the definitions of my personal macros. It turns out to be not-so-easy and the naive replacement of \def by \newcommand does not always work. Is there a standard way of doing that?
Let me give two examples:
(1) \def\res{\texttt{Res}\left(#1\right)} I cannot replace def by newcommand
(2) \def\io{\infty} I can replace def by newcommand
In a submission there should be no \def, because the copy editors are afraid tha a user does things such as
\def\c{\gamma} so making it impossible to typeset a paper by a Turkish coauthor whose name contained “Ş”. It really happened.
You may possibly use a few \renewcommand instructions, but mark them clearly. I'm thinking to something quite safe like
\renewcommand{\epsilon}{\varepsilon} but you should be certain not to modify important commands.
Your definition of \res is wrong anyway, because you're using a parameter in the replacement text without announcing it. Possibly
\newcommand{\res}[1]{\operatorname{\mathtt{Res}}(#1)} I discourage you from
\newcommand{\io}{\infty} because the standard command is semantic, yours isn't and the gain is really not worth the pain of remembering another command.
In any case, if using \newcommand returns an error about the command being already defined, avoid switching to \renewcommand unless you precisely know what you're doing (like in the \epsilon case, but not in the \c case).
\newcommand\box, then after seeing the error message they did \renewcommand\box and wondered why everything was running havoc :-) \box or \fi are two of my favorite examples when teaching LaTeX.
\expandafter\let \expandafter\getridofdef \csname def\endcsnameand replace all occurrences of\defby\getridofdef. Now, Your document includes no\defat all.\newcommanddoesn;t work,\renewcommandshould. Better uet, use another name for the macro, one that isn't alreacy being used. If you intend to change an existing definition, don't do it!\def. I wanted to point out that the rule "no \def in the document" is absurd. Journal needs a skilled editor who know TeX well. No to give absurd rules. The example about\def\cis somewhat historical. Now, we have Unicode TeX engines, so Turkish coauthor should write “Ş” directly. If not then the editor will correct it or ask the author not to use such historical macros. LaTeX needs to free itself from the burden of history.