<!-- This example illustrates the circle_by_three_points and center_of_circle constraints.

	Analogous WIRIS code:
	P = point(-1,-1)
	Q = point(1,-1)
	R = point(-1,1)
	c = circumference(P,Q,R)
	C = center(c)
-->


<construction>
	<elements>
		<point id="P">
			<homogeneous_coordinates>
				<double>-1</double>
				<double>-1</double>
				<double>1</double>
			</homogeneous_coordinates>
		</point>
		<point id="Q">
			<homogeneous_coordinates>
				<double>1</double>
				<double>-1</double>
				<double>1</double>
			</homogeneous_coordinates>
		</point>
		<point id="R">
			<homogeneous_coordinates>
				<double>-1</double>
				<double>1</double>
				<double>1</double>
			</homogeneous_coordinates>
		</point>
		<point id="C">
			<homogeneous_coordinates>
				<double>0</double>
				<double>0</double>
				<double>1</double>
			</homogeneous_coordinates>
		</point>
		<circle id="c">
			<matrix>
				<double>1</double>
				<double>0</double>
				<double>0</double>
				<double>0</double>
				<double>1</double>
				<double>0</double>
				<double>0</double>
				<double>0</double>
				<double>-2</double>
			</matrix>
		</circle>
	</elements>
	<constraints>
		<circle_by_three_points>
			<circle out="true">c</circle>
			<point>P</point>
			<point>Q</point>
			<point>R</point>
		</circle_by_three_points>
		<center_of_circle>
			<point out="true">C</point>
			<circle>c</circle>
		</center_of_circle>
	</constraints>
</construction>

