Fwd: Re: There is a severe problem with EQN and square roots

[forgot to Cc the list]

Forwarded message from onf on Mon Mar 2, 2026 at 1:36 PM:

On Mon Mar 2, 2026 at 11:36 AM CET, G. Branden Robinson wrote:
> At 2026-03-02T10:21:50+0100, onf wrote:
> > the problem with square roots in groff's eqn is that groff only knows
> > a single type of square root (the small one). Therefore if an equation
> > requires a higher square root, the only thing groff can do is set the
> > small one in a larger size, and you get an overly thick, overly wide
> > symbol as a result.
> 
> It's so old that Kernighan and Cherry noted it in the eqn users' guide.
> 
> https://github.com/g-branden-robinson/retypesetting-mathematics/releases/download/v1/eqnuser.pdf
> 
> See §10.

I am aware of that, but Sigfrid might not be.

It's also worth remembering the context in which they were writing it,
though. The printers of the time were fairly limited in all sorts of
ways including the number of glyphs they could work with. In today's
conditions, however, their advice would be fairly stupid. The proper
-- and technologically absolutely feasible -- solution is to make eqn
capable of setting typographically correct large square roots, not
insisting users change their equations. The logic is hardly different
from adding support for longer identifiers rather than insisting that
users find a way to name their macros and registers using only two
characters.

Cheers,
onf