How to auto-repeat the last part of a previous slide?
There is one really annoying thing with the presentations, especially scientific ones. When the parts of a slide are appearing one by one, the first part is shown for several minutes, whether the last one is shown just for a dozen of seconds. And often when the last part appears, you are still looking through the previous parts, and the slide suddenly changes before you apprehended the last part.
The solution is to repeat the last part on the next slide as follows. After the slide is erased (i.e. the next slide starts), all of its parts dissapear except the last one, which is just shadowed and still readable. So, the first page of next slide contains the first part of next slide AND the shadow of the last part of the previous slide, so the narration is not disrupted. And only after that this last part will finally disappear.
I guess that it is not a problem to make such a presentation with an existing toolbox, but most people are accustomed with just basics of the package, so one needs a really simple way, just one line like "\sloppy" in LaTeX which will add shadowing to all the slides. The only problem is to check if there is enough space for the shadow. If not, then no shadow on that slide. P.S. I'm sorry if this is not a new idea, I've just never seen anything like this.