Let there be these three hyperbolic paraboloids: x = yz, y = zx, z = xy. These three hyperbolic paraboloids intersect externally along the six edges of a tetrahedron and internally along the three axes. The internal intersections are loci of double points. The three loci of double points: x = 0, y = 0, and z = 0, intersect at a triple point at the origin.
Let there be these three hyperbolic paraboloids: x = yz, y = zx, z = xy. These three hyperbolic paraboloids intersect externally along the six edges of a tetrahedron and internally al:ong the three axes. The internal intersections are loci of double point.s. The three loci of double points x = 0, y = 0, and z = 0, intersect at a triple point at the origin