New environments

One can create new environments and renew existing ones with following commands:

\newenvironment{env_name}[number_of_parameters]{def_begin}{def_end} \renewenvironment{env_name}[number_of_parameters]{def_begin}{def_end}

where

def_begin is the text substituted for every occurrence of \begin{env_name};
def_end is the text substituted for every occurrence of \end{env_name};
if the number of parameters is zero, the square bracket can be omitted, or used as [0];
there can be at most 9 parameters; they are referred to in def_begin by #1, #2,..., #9;
NOTE: these parameters cannot be refered to in def_end.

Here are a few examples:

\newenvironment{starquote} {\begin{center}***\end{center}}{\begin{center}*****\end{center}} \newenvironment{namedquote}[1]{\textbf{#1:}\begin{quote}}{\end{quote}}

how they are used:

\begin{starquote} This part is so remarkable that we decided to separate it from the rest. \end{starquote} \begin{namedquote}{equinox} the moments of the year when the sun crosses the equatorial plane of the earth \end{namedquote}

and the approximate way this would look:

*** This part is so remarkable that we decided to separate it from the rest. *****
equinox:
the moments of the year when the sun crosses the equatorial plane of the earth