IfcStairFlight doesn't export the IfcSlab.FLOOR it should be connected to

I'm currently testing REVIT capabilities to export in IFC and it's pretty convenient to use. But I think there is one important feature missing when exporting an IfcStair.

The exporting of an IfcStair as an aggregation of components that describe the stair is perfect and follow what's described inside this document [MVC-696](http://www.blis-project.org/IAI-MVD/Concepts/MVC-696.pdf).

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But if you look at the description of an [IfcStairFlight](https://standards.buildingsmart.org/IFC/RELEASE/IFC2x3/FINAL/HTML/ifcsharedbldgelements/lexical/ifcstairflight.htm).
> An IfcStairFlight normally connects the floor slab of zero to two different storeys (or partial storeys) within a building. The connection relationship between the IfcStairFlight and the IfcSlab is expressed using the IfcRelConnectsElements relationship.

In fact this information allow the user to know from which IfcSlab the stair is starting and to which slab it leads. Without this information you can't navigate inside the building properly.

Is that the kind of feature you are planning to implement or is it something out of the scope of the Revit-Ifc plugin ? (My understanding of IfcStairFlight might also be wrong)

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There is multiple way you can handle this connection outside of REVIT. Like 3D proximity between the IfcStair representation and the IfcSlab.FLOOR representation. But it would be perfect if REVIT was able to handle this kind of situation by himself

Start by reviewing the IFC2x3 IfcStairFlight description and the MVC-696 document cited in the issue, then trace how the exporter represents IfcStair components and IfcSlab.FLOOR elements. The work is done when exported stair flights contain the appropriate IfcRelConnectsElements relationships to their connected floor slabs and the result supports navigation between storeys.

Written by the indexing model from the issue text.