Here is a list of all concepts with brief descriptions:

Npgl
RAnyShapeConcept	Any concrete geometry type or the runtime Shape wrapper
RBoundedConvexConcept	Bounded convex primitives
RBoundedPolygonalConcept	Bounded polygonal primitives, convex or not
RConvexConcept
RDiskConcept
REmptyShapeConcept
RHalfplaneConcept
RHalfplaneIntersectionConcept
RLineConcept
RMinkowskiSummableConcept	Shape pairs whose Minkowski sum Pangolin can represent
RMonotoneChainConcept
RNumericType
ROrientedLineConcept
ROrientedSegmentConcept
RPointConcept
RPolygonalRegionConcept	Bounded polygonal regions: exactly the shapes a PolygonSet can always represent
RPolygonConcept
RPolygonSetConcept
RPolygonWithHolesConcept
RPolylineConcept
RRationalConcept
RRayConcept
RRectangleConcept
RSegmentConcept
RShapeConcept
RTransformationConcept
RTriangleConcept
RUnboundedConvexConcept	Unbounded convex polyhedral primitives