void IClassExpressionVisitor.Visit(
     IObjectComplementOf objectComplementOf
     )
 {
     _enter?.Visit(objectComplementOf);
     objectComplementOf.ClassExpression.Accept(this);
     _exit?.Visit(objectComplementOf);
 }
 public virtual void Visit(IObjectComplementOf objectComplementOf)
 {
 }
 bool IClassMembershipEvaluator.Evaluate(
     IObjectComplementOf objectComplementOf,
     object individual
     ) => !objectComplementOf.ClassExpression.Evaluate(
     this,
     individual);