I’m at a maths conference now, and thus I am exposed to numerous slides (usually done in whatever-TeX—`beamer`

is quite popular, but one can encounter other tools, too; I’ll be probably the only one with ConTeXt-based slides, though). Today I saw something which really did bother me, to the extent that I’m going to warn all of you reading this: *please don’t do that*!

What was the offender? An innocent-looking pair of equations:

(let me add that all *something*s in both equations were identical).

Now I understand that this is *mathematically* correct, but I daresay it’s *typographically* wrong. *Very* wrong. Just compare it to this:

See what I’m talking about? While these two equations were parallel, the author took some pains to actually *hide* this fact from the audience.

On a sidenote, I am curious *why* exactly did this guy do that? He must have done it on purpose, since the most natural way to typeset such a formula is to use kill-and-yank, er, sorry, copy-and-paste. Perhaps it was a more or less subconscious way to avoid a minus in front of the former formula (and possibly a zero in the latter one), which seems to me almost atavistic.

And all this rant leads to a sad conclusion: do people at conferences really care about what they are trying to communicate? (Needless to say, this wasn’t the worst presentation, in fact, it was far from it; it was just an interesting mistake and that is why I decided to share it.)