Symbоls fоr Relаtiоnаl Algebrа Expressions and Other Symbols Symbols for relation schemas: R, S, T Symbols for relations: R, S, T, ∅ Symbols for Relational Algebra operators: ∪, -, π, σ, ρ, ⨯, ∩, Δ, ÷, ⨝, ⟗, ⟕, ⟖, ⋉, ⋊, ▷ Symbols for logical connectives: ∧, ∨, ¬ Symbols for comparison predicates: , =, ≤, ≥, ≠ Symbols for set-theoretical operations: ∈, ∉, ⊆, ⊂, ⊇, ⊃ Other mathematical symbols: ⊥, ⋅, ∃, ∀, ∘, ←, → All names (for example, for relations and attributes) should be written in normal font (no italics) to increase readability. All symbols should be surrounded by blanks to increase readability. Database schema Animals(AnimalID, Species, Name, DateOfBirth, Gender, HabitatID, Origin, ArrivalDate, DietType)Habitats(HabitatID, Type, Size, Location, CleaningSchedule, EnvironmentControlSettings)ZooStaff(StaffID, FirstName, LastName, Role, Department, HireDate, Qualifications, ContactNumber)AnimalHealthCare(StaffID, AnimalID, CareDate, Treatment, Notes)VisitorTours(TourID, Date, Time, GuideStaffID, RouteDescription, Theme, Duration, GroupSize)Maintenance(MaintenanceID, HabitatID, Description, Year, Date, StaffID, Status, Priority)ConservationPrograms(ProgramID, Name, Description, StartDate, EndDate, ResponsibleStaffID)ZooEvents(EventID, Name, Date, Time, Location, OrganizerStaffID, TargetAudience, Budget) Query Find the names of staff members who have only guided visitor tours with less than 10 people or more than 20 people.
Fоr the fоllоwing MATLAB code, whаt is the output result of m - n? A = [1 2 2 3 3 1; 0 1 -1 0 2 -2; 0 0 1 -2 0 3]; b = [1 2 0 -1 -2 0]; [m, n] = size([A; b]); m - n