Entity-to-entity distance implementations with freespace flag is true, differ from OpenSCENARIO standard

[HansRobo]

Describe the bug

The Entity-to-entity distance implementation, under entity coodinate system and the freespace flag is true, is differs from OpenSCENARIO standard.

I discribed its standard definition and current inplementation in the figure below.

And, the one of implementations is here.
https://github.com/tier4/scenario_simulator_v2/blob/master/openscenario/openscenario_interpreter/src/syntax/relative_distance_condition.cpp#L71-L84

Expected behavior

The implementation conforms to standards
( At least, this limitation should list up to the limitations in the document )