I've encountered a MetaPost issue, and since many MetaPost users also use
ConTeXt (and vice-versa), I am posting this question on both lists.

The command

> show identity rotated 270 yscaled 0.5;

outputs

(0,0,0,1,-0.5,0)

as expected, while the command

> show identity transformed (0,0,0,1,-0.5,0);

errors with

---
! Missing `)' has been inserted.
<to be read again>
                   ,
l.26 ^^Ishow identity transformed (0,0,0,1,
                                           -0.5,0);
---

I am using MetaPost 1.504, and the problem seems to be that MetaPost does
not like me using the sextuple (0,0,0,1,-0.5,0) directly, but this is the
most convenient method for me to describe my transformations.  Is this a
bug in MetaPost, or am I not allowed to use transformations directly with
sextuples?

Troy Henderson