I am used to define some complicated and frequent mathematical expressions to be able to use them easily in my papers. For example I have defined

`\def\c{{\mathbb{C}}}`

for `$\mathbb{C}$`

(the field of complex numbers).

However sometimes there are more complicated formulas and mathematical expressions which involve one, two, or more variables (or parameters). For example, consider `$Hom_{\mathbb{Z}} (M,N)$`

which involves two variables `$M$`

and `$N$`

.

My question is "how can I define such expressions generally with the ability to change the variable inside them.

## Best Answer

These are not variables in "typesetting sense". You

coulddefineand then use

for getting

but this is no way more expressive or readable than

after having defined

Actually, I contend that the latter form is

muchmore readable than the first one.Note. Be careful in saying

because

`\c`

is an "accent command" in LaTeX (`\c{c}`

is used in French, Albanian, Turkish, Portuguese, Catalan and other languages). Always use`\newcommand`

or, if you really know what you're doing,`\renewcommand`

; but don't redefine general use commands: if one of your bibliography items contains a "รง" you'll regret having redefined`\c`

.