Re: Mixed L2R and R2L paragraphs and horizontal scroll

[Richard Stallman]

    It seems to me that you'd prefer to keep R2L and L2R texts rigidly tied
    (column-wise), if i understand you correctly (i.e. Stefan's "rigid
    scrolling"). But I don't know whether this is well-defined without
    pre-supposing some arbitrary text with to begin with (and what do you do
    with proportional fonts? Ligatures?).

Rigid hscrolling is well defined with proportional fonts.

I don't think Emacs tries to do hscroll properly with proportional
fonts even now with all text L2R.  It would be good to implement this.
Handling R2L text too in a rigid way would not be much harder.