Creates a partition out of a list l of one or more regions.
Partitions are used by nurbs surfaces to define the subset of their paramtetric domain which shall be displayed (points are rendered if they lie in an odd number of loops; the orientation of the loops doesn't matter, all loops are counted positive).
The keyword "partition" is a bit misleading, the regions are allowed to intersect themself or each other, conflicts are resolved with the above mentioned odd winding rule.
l must be a typeless node to which one or more region type nodes are connected.
The following variations of this keyword exist (some of them define the same internal structures, and are only defined to allow consistent naming conventions):