The string to trim at. This can contain a
mixture of curves, edges, features, sketches,
and faces. If features are included then the
curves produced by that feature are input as
the string to trim or bounding string. If
sketches are included then the curves in the
sketch are input as the string to trim or the
bounding string. If faces are included the
edges of the faces are input as the string to
trim or the bounding string.

If trimming to an object, then the num field in
this structure should be set to 0. Note that
the field dir in the string structure indicates
which end of the bounding string should be
trimmed or extended.

The object to trim at. This object
can be a face, point, datum plane,
or datum axis. If trimming to a
string then this should be set to
NULL_TAG.

Indication if the following point
should be used to select between
multiple intersection points.

The point that is used to select
one of multiple intersection
points. The intersection point
closest to this point will be used.