I'm trying to create an environment which uses xparse style arguments but I have to be able to use the whole environment content in the environment definition, e.g. as an argument. Ideally I'd like ...
I want to define an environment with LaTeX3 where I can supress the indention in the first line. For LaTeX2e you can use \@afterindentfalse\@afterheading. The example use this combination. But I want ...