In 1889 , Giuseppe Peano introduced the following two axioms: P1. If A,B, and C are three non-collinear points, D and E are such that A?B?D and A?E?C, the there is a point F such that E?F?D and B?F?C. and P2 If A,B, and C are three non-collinear points, D and E are such that A?B?D and B?C?E, the there is a point F such that D?E?F and A?F?C. It is easy to show that I1-I3, B1-B4 imply P1 and P2. Is is true that I1-I3, B1-B3, P1, P2 imply B4? If yes, provide a proof, if no, a counterexample (an independence model).