i. Prove that a set of four points in a projective plane P (i.e. dim P = 2) form a projective frame if and only if no three of the points are collinear, i.e. no three lie on the same projective line.
ii. Find a necessary and sufficient condition for five points to form a projective frame in a three dimensional projective space P.
This is a proof regarding a projective frame and explains necessary and sufficient conditions for points to form a frame.