public ExistanceForm(IExistanceForm form)
 {
     _form = form;
 }
 public ApproachForm(IApproachForm form)
 {
     _form = form;
 }
 public ExistanceForm()
 {
     _form = new EmptyForm();
 }
 public SubjectPredicateRelationForm(ISubjectPredicateRelationForm form)
 {
     _form = form;
 }
 public ApproachForm()
 {
     _form = new EmptyForm();
 }
 public ExistanceForm(IExistanceForm form)
 {
     _form = form;
 }
 public SubjectPredicateRelationForm()
 {
     _form = new EmptyForm();
 }
 public ExistanceForm()
 {
     _form = new EmptyForm();
 }
 public SubjectPredicateRelationForm(ISubjectPredicateRelationForm form)
 {
     _form = form;
 }
 public SubjectPredicateRelationForm()
 {
     _form = new EmptyForm();
 }
 public ApproachForm()
 {
     _form = new EmptyForm();
 }
 public ApproachForm(IApproachForm form)
 {
     _form = form;
 }