Re: [Groff] Fw: problem with pic

[Keith Marshall]

On Thursday 20 March 2008 18:31, Y T wrote:
> To me it is perfectly natural that
>        line from 1,1 then up 1
> is different from
>        line then up 1

Well yes, they are different in the sense that the former explicitly 
moves to point (1,1), while the latter simply starts plotting from the 
current position, wherever that may be.  Other than that, they are the 
same: draw a line segment of implicit length in the current direction; 
follow that with a second line segment, of explicit length 1 unit, in 
the upward direction.

> In the first case, there is a very clear intuitive specification of a
> path that starts at 1,1 and then goes up 1 -- it is not ambiguous.

No, it isn't ambiguous.  However, you make the assumption that the 
implicit length of a line segment is zero units; in pic, this isn't so.
What would you expect this minimal example to produce?

  .PS
   line
  .PE

Regards,
Keith.