I want to know the answer to the following question:
Who used tuple calculus to show the functionality of databases?
All the background I'm provided with is that "Using a branch of mathematics known as tuple calculus, he demonstrated that such a system could support all the operations of normal databases (inserting, updating etc.) as well as providing a simple system for finding and returning sets of data in a single operation.". Is that enough to answer the question?
Answer: no