A point T is chosen inside a triangle ABC. Let A1, B1, and C1 be the reflections of T in BC, CA, and AB, respectively. Let Ω be the circumcircle of the triangle A1B1C1. The lines A1T, B1T, and C1T meet Ω again at A2, B2, and C2, respectively. Prove that the lines AA2, BB2, and CC2 are concurrent on Ω.Proposed by Mongolia IMO Shortlistgeometryconcurrency