C# (CSharp) ComputerAlgebra Set.Contains примеры использования

Пример #1

 public override bool Matches(Expression E, MatchContext Matched)
 {
     return((ReferenceEquals(Ring, null) || Ring.Contains(E)) && Matched.Matches(this, E));
 }

Пример #2

 public override bool Matches(Expression E, MatchContext Matched)
 {
     return((Ring is null || Ring.Contains(E)) && Matched.Matches(this, E));
 }