
theorem
  for C being FormalContext for CP being quasi-empty ConceptStr over C
st CP is strict FormalConcept of C holds CP = Concept-with-all-Objects(C) or CP
  = Concept-with-all-Attributes(C)
proof
  let C be FormalContext;
  let CP be quasi-empty ConceptStr over C;
  assume
A1: CP is strict FormalConcept of C;
  now
    per cases by Def8;
    case
      the Intent of CP is empty;
      hence CP = Concept-with-all-Objects(C) by A1,Th25;
    end;
    case
      the Extent of CP is empty;
      hence CP = Concept-with-all-Attributes(C) by A1,Th25;
    end;
  end;
  hence thesis;
end;
