public static Alphabet operator +(Alphabet a, Alphabet b) { var c = new Alphabet(); foreach (var c1 in a) { c.Add(c1); } foreach (var c1 in b) { c.Add(c1); } return(c); }
public static Alphabet operator -(Alphabet a, Alphabet b) { var c = new Alphabet(); foreach (var c1 in a) { if (!b.Contains(c1)) { c.Add(c1); } } return(c); }