Hi Pior,

> since one would assume intuitively that a circle segment is a subset of the group "curve" (even though in the DXF sense they are different entities).

The term "Curve" in MoI terminology has a specific meaning, it's a wire object that has a child list of Curve Segments.

An arc that is contained inside a parent curve is not a "Curve" in MoI, it's a "Curve Segment".

- Michael