#### Description:

This attribute indicates the fraction of the Region which is of interest. AST does not use this attribute internally for any purpose. Typically, it could be used to indicate the fraction of the Region for which data is available.

The supplied value must be in the range 0.0 to 1.0, and the default value is 1.0 (except as noted below).

Type:

  Floating point.

#### Applicability

##### Region

All Regions have this attribute.

##### CmpRegion

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

##### Prism

The default FillFactor for a Prism is the product of the FillFactors of its two component Regions.

##### Stc

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