Am 16.12.2010 um 18:28 schrieb Vedran Miletić:

> 2010/12/16 Jonas Stein <news@jonasstein.de>
> >>> \define[1]\myoneliner{#1 \par }
> >>> raises an error.
> 
> >> \define[1]\myoneliner{#1 \endgraf}
> 
> works fine. Thank you!
> 
> > This is also nicely covered in TeXBook.
> > Alternatively \long\def might work.
> 
> \long\define[1]\myoneliner{#1 \par } 
> fails too
> 
> \long\def\myoneliner#1{#1 \par} should work.

You don’t need \long in this case, the problem is that
\define itself isn’t defined as \long while in mkiv
all commands are defined as \long.

Wolfgang