A property of X(15316)

Let h be the affine transformation that carries ABC onto DEF (anticevian triangle of the circumcenter). For any line ℒ through O (circumcenter), let ℒ' be the image of ℒ under h, and let U be the intersection point of ℒ and ℒ'. Then the line h(U)h-1(U) pass through X(15316), when ℒ rotates around O.


Angel Montesdeoca, Mars 7, 2021