Complex sentence: It was the 75th running of the Prix de l'Arc de Triomphe and was won by Helissio, ridden by Olivier Peslier and trained by Elie Lellouche.
Split into simpler sentences: It was the 75th running of the Prix de l'Arc de Triomphe, and it was won by Helissio. The winner was ridden by Olivier Peslier and trained by Elie Lellouche.