// Use _comparer to keep equals properties intact; don't want to choose one of the comparers. public bool Equals(SortedSet <T>?x, SortedSet <T>?y) => SortedSet <T> .SortedSetEquals(x, y, _comparer);
public bool Equals(SortedSet <T> x, SortedSet <T> y) { return(SortedSet <T> .SortedSetEquals(x, y, this.comparer)); }