Let P be a point, A'B'C' its pedal triangle, A”B”C” the circumcevian triangle of P in A'B'C'.  Let B*, C* be the orthogonal projections of B, C on AP. The lines B*B”, C*C” intersect at Xa. Define analogously Xb, Xc. The lines  AXa, BXb, CXc concur.