Database System class

Please provide algebra AND calculus expressions for each of the queries. So 4 in total. Thank you

Provide algebra and calculus expressions for the following queries EXERCISE CITY (Name, State, Population) CROSSING(City, River) RIVERName, Length) Show name, state and population for cities with more than 20000 people and crossed by the river Rio Grande or the river Red River 1. Find cities crossed by at least two rivers, showing the name of the city and the name of the longest river crossing such city 2