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Re: radical thoughts


>> Well, if we could assume e-TeX, the simplest solution would be to propose
>> revising the algorithm for the placement of radicals to be more like the
>> delimiters, i.e.

> careful, there is a distinction between etex and NTS, not sure if
> according to etex ideas this can be incorporated. but it is worth
> thinking about

I was thinking about e-TeX "enhancements" rather than "extensions",
i.e. those kinds of changes that need to be activated explicitly.

>> It would be interesting to check out if there are any math extension
>> fonts designed for TeX where the actual height of the radical glyphs
>> is any different from the default rule_thickness.  If not, we could
>> safely assume that the mechanism of deducing the rule height from 
>> the glyph metrics isn't really needed anyway.

> i find this argument dangerous. all we have experienced so far is that
> because Don made these kind of implicit assumptions we run into
> problems because fonts other than cm do not necessarily obey
> them. thus i would vote against an extension that builds in another
> unproven assumption.

[errorlog.tex]
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* 21 Mar 1978
# 10pm. The computer is rather heavily loaded tonight.
F145. Don't forget \\{thickness} when making a square-root sign (see \#131).
        [The rule thickness will later be derived from the character height.] @737
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As far I can tell, TeX78 originally used to take the rule_thickness
from the fontdimens, but this was changed in TeX82 taking it from
the character heigt.  Even after this change, however, the radicals
in the CM fonts used character height = rule_thickness by design, 
so no actual use was made of this feature.

As for other font sets, I think the different heights in the Mma fonts
are a design bug.  Perhaps Berthold can explain why there are different
heights in MTEX, or is this a bug as well?

Cheers, Ulrik.