@Pure
	public DoubleProperty z1Property() {
		if (this.p1.z == null) {
			this.p1.z = new SimpleDoubleProperty(this, MathFXAttributeNames.Z1);
		}
		return this.p1.z;
	}
@ Pure public DoubleProperty z1Property ( ) { if ( this . p1 . z == null ) { this . p1 . z = new SimpleDoubleProperty ( this , MathFXAttributeNames . Z1 ) ; } return this . p1 . z ; }
Replies the property that is the z coordinate of the first segment point.

@return the z1 property.