[math-font-discuss] Ugly drawn rules in Adobe Reader

[Taco Hoekwater]

Karl Berry wrote:
> Hi Taco,
> 
>     Specification would be like \mathchardef, say:
> 
> \rulechar"0130 or \rulechardef\foo="0130, then, maybe?
> And maybe it should be \mathrulechar?

\mathrulechar is a better name, yes.

> Is there a character in an existing font that can be used, or does a new
> font have to be created?

A suitable character has to be available/created. It would be a
short hyphen, lying on top of the baseline, with no sidebearings.

> And how is it going to be used?  Sorry, I'm still not clear on this.
> \radical and such are primitives, their functionality cannot be
> duplicated in macros, can it?

The fact that there has been a definition of:

   \mathrulechar="0130

somewhere in the TeX source, would make subsequent \radical commands
use a suitable number of repetitions of the character "30 in math
family 1 instead of the horizontal rule it draws currently.
No macros involved.

> I'm puzzled as to why my results are so different from yours.  Nothing I
> see seems nearly bad enough to be worth the enormous and permanent
> hassle of defining a new primitive.

It is related to the screen resolution, I think. Anyway, I do not
consider a few dozen lines of code an enormous hassle, and also:

> I have seen the misaligned sqrt's before, but I guess I always assumed
> that something in pdftex was outputting the horizontal part in the wrong
> place

that line of thought is precisely why I believe it makes sense
to add a primitive :-)

I do not have the source of my example here, but it is a plain
tex file that starts with

   $$\sqrt{\sqrt{\sqrt{\sqrt{\sqrt{\sqrt{x+1}}+1}+1}+1}+1}$$

(I think)

Taco