Triángulos simétricos del triángulo preceviano de un punto, perspectivos con el triángulo de referencia

(Paris Pamfilos,) http://tech.groups.yahoo.com/group/AdvancedPlaneGeometry/message/33
Triangle A'B'C' is perspective to ABC w.r. to point P. For which points Q, the symmetry S_Q w.r. to Q, produces
A''B''C'' = S_Q(A'B'C') also perspective to ABC?

(Paul Yiu)
Let's take A'B'C' to be the ANTICEVIAN triangle of P.

This conic [locus of Q] is the bicevian conic C(G,P'), where P' is the commonpoint of the circumconics C_P (with perspector P) and C'_P (with center P).