[luatex] \predisplaydirection from etex in luatex has no effect

[Taco Hoekwater]

Vafa Khalighi wrote:
> Can you explain the offered functionality? That is not clear to me from
> 
>> the example code.
>>
>>
> It is an internal read/write integer, initialised by e-TeX to indicate the
> direction of the last partial paragraph before a display; it is used to
> control the placement of elements such as equation numbers, and can be
> explictly set to affect this placement.

Ok, now I only need the exact meaning of the values.

Best wishes,
Taco