Complex sentence: In mathematics, the symmetric group, "S n", has a poset structure given by the weak order of permutations, given by "u ≤ v" if Inv ("u ") is a subset of Inv ("v").
Split into simpler sentences: In mathematics, the symmetric group, "S n", has a poset structure given by the weak order of permutations. We say that "u ≤ v" if Inv ("u ") is a subset of Inv ("v").