[AUCTeX] Re: Filling in math environments

[Brett Presnell]

Small error in that last query.  What I meant to say was ...

Is there any way to turn off filling in latex math environments without
turning off filling altogether?

What I actually want is something more specific: suppose I am in the
midst of typing something like 

\begin{equation*}
  \varbw(\epsilon^*)
  = n^{-1} \sum_{i=1}^n (\resid_i - \resbar_n)^2
  = n^{-1} \sum_{i=1}^n [
  \{ \error_i - \tp{x_i}(\betares_n - \beta) \} 
  - \{\errbar_n - \tp{\xbar_n} (\betares_n - \beta) \}]^2
  = n^{-1} \sum_{i=1}^n (\error_i - \errbar_n)^2
  +
\end{equation*}

when I realize that I am going to need to insert a split environment.
So I select lines 1--7 of the equation* environment above and type "C-c
C-e split Ret".  This gives me

\begin{equation*}
  \begin{split}
    \varbw(\epsilon^*) = n^{-1} \sum_{i=1}^n (\resid_i - \resbar_n)^2
    = n^{-1} \sum_{i=1}^n [ \{ \error_i - \tp{x_i}(\betares_n - \beta)
    \} - \{\errbar_n - \tp{\xbar_n} (\betares_n - \beta) \}]^2 =
    n^{-1} \sum_{i=1}^n (\error_i - \errbar_n)^2 +
  \end{split}
\end{equation*}

when what I want is

\begin{equation*}
  \begin{split}
    \varbw(\epsilon^*)
    = n^{-1} \sum_{i=1}^n (\resid_i - \resbar_n)^2
    = n^{-1} \sum_{i=1}^n [
    \{ \error_i - \tp{x_i}(\betares_n - \beta) \} 
    - \{\errbar_n - \tp{\xbar_n} (\betares_n - \beta) \}]^2
    = n^{-1} \sum_{i=1}^n (\error_i - \errbar_n)^2
    +
  \end{split}
\end{equation*}

Note that I want indentation but not filling.