\newtheorem and \newtheoremstyle

[Daniel Lohmann]

Hi,

In my thesis I have to define a couple of terms and I thought about using 
the amsthm package which offers the \newtheorem and \newtheoremstyle 
commands to generate environments for theorem-like structures.

So I added to my layout file a new style $Definition to my layout file:

Counter
  Name defn
End
Style $Definition
  Margin          First_Dynamic
  LatexType       Environment
  LatexName       defn
  LabelSep        xx
  NextNoIndent          1
  ParIndent       MMM
  ParSkip         0.8
  ItemSep         0.2
  TopSep          0.5
  BottomSep       0.5
  ParSep          0.3
  Align           Block
  AlignPossible   block, left, center, right
  LabelType       Counter
  LabelCounter    defn
  LabelString     "Definition @[EMAIL PROTECTED]:"
  LeftMargin      MM
  RightMargin     MM
  LabelFont
    Family        Sans
    Shape         Up
    Series        Bold
    Size          Small
  EndFont
  Preamble
    \usepackage{amsthm}
\newtheoremstyle{mydefinition}{\topsep}{\topsep}{}{}{\sffamily\bfseries}{:}{1em}{}
    \theoremstyle{mydefinition}
    \newtheorem{defn}{Definition}[chapter]
  EndPreamble
End

All this works fine so far. However, so far I have not been able to solve 
two issues, a LyX-related (1.4.5) and a more LaTeX-related:

1) How can I pass the optional title parameter from LyX to the "defn" 
environment? The "Insert->Short Title" command I usually use for this 
purpose is always disabled (greyed) when I am editing a definition. Is 
there a specific flag I can give in the layout definition to enable it?

2) How can I indent the whole thing? The \newtheoremstyle command offers a 
parameter for first line indentation, but I would like to indent the whole 
thing by, lets say, 2em. Any idea how to achieve that with theorems?

Thanks a lot!

Daniel