Given a set of points U belonging to a plane defined over a field of cardinality q^2, return true if U is a unital, i.e. U is a set of q^3 + 1 points with property that every line meeting two points meets exactly q + 1 points.

Given a unital U in the projective plane P, return the set of tangents to the points of U.

The set of intersections of the unital U with the tangents to U which pass through the point p.