\newcommand
\newcommand{cmd}[args]{def} \renewcommand{cmd}[args]{def}
These commands define (or redefine) a command.
- cmd A command name beginning with a \. For \newcommand it must not be already defined and must not begin with \end; for \renewcommand it must already be defined.
- args An integer from 1 to 9 denoting the number of arguments of the command being defined. The default is for the command to have no arguments.
- def The text to be substituted for every occurrence of cmd; a parameter of the form #n in cmd is replaced by the text of the nth argument when this substitution takes place.