Re: Give parts of commands/definitions to...

> def vvec right body
> { pmatrix strut { Yes }  body }
> 
> The body is nor parsed again,

That's right, this will not work.  Body parameters like the
parameter of pmatrix do have this problem.  However, you can
work around it with a macro:

    macro vvec { pmatrix strut { Yes } }

This does a token substitution of vvec by pmatrix strut { Yes }.
From a programming language point of view this is not very nice;
but there is a lot of it in the standard packages.

Jeff