#### Description:

This attribute controls whether points on the boundary of a Region are considered to be inside or outside the region. If the attribute value is non-zero (the default), points on the boundary are considered to be inside the region (that is, the Region is `"` closed`"` ). However, if the attribute value is zero, points on the bounary are considered to be outside the region.

Type:

  Integer (boolean).

#### Applicability

##### Region

All Regions have this attribute.

##### PointList

The value of the Closed attribute is ignored by PointList regions. If the PointList region has not been negated, then it is always assumed to be closed. If the PointList region has been negated, then it is always assumed to be open. This is required since points have zero volume and therefore consist entirely of boundary.

##### CmpRegion

The default Closed value for a CmpRegion is the Closed value of its first component Region.

##### Stc

The default Closed value for an Stc is the Closed value of its encapsulated Region.

##### Moc

The Moc class ignored this attribute, and the behaviour for boundary points is undefined (i.e. they may be inside or outside the Region, depending on the position being tested and the nature of the Moc).
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