Given an acute triangle ABC, (c) its circumcircle with center O and H the orthocenter of the triangle ABC. The line AO intersects (c) at the point D. Let D1,D2 and H2,H3 be the symmetrical points of the points D and H with respect to the lines AB,AC respectively. Let (c1) be the circumcircle of the triangle AD1D2. Suppose that the line AH intersects again (c1) at the point U, the line H2H3 intersects the segment D1D2 at the point K1 and the line DH3 intersects the segment UD2 at the point L1. Prove that one of the intersection points of the circumcircles of the triangles D1K1H2 and UDL1 lies on the line K1L1. geometrySymmetricconcurrencyconcurrentorthocenter