Consider the following instance of a relation District – Which of the District…

Step 1: Apply the selection σₙₐₘₑ≠"AJ" to the relation District. This filters out the row where the name is "AJ", leaving the rows for JA and MM. Step 2: Apply the projection πₙₐₘₑ to get the names of the remaining districts. This gives {JA, MM}. Step 3: Apply σₚₒₚᵤₗₐₜᵢₒₙ>5 to find districts with population greater than 5. Only AJ has population 50, so this gives {AJ}. Step 4: Apply πₙₐₘₑ to get the names of districts with population > 5. This gives {AJ}. Step 5: Apply σₙₐₘₑ="AJ" to get the district with name AJ. This gives {AJ}. Step 6: Apply πₙₐₘₑ to get the name AJ. This gives {AJ}. Step 7: Find the intersection of {AJ} and {AJ}, which is {AJ}. Step 8: Perform the set difference {JA, MM} − {AJ}, which removes AJ from the set, leaving {JA, MM}. Final result: {JA, MM}.