To what extent is the universe infinite?
Agent Smith is a philosopher; he provokes thinking, which is, of course, frowned upon in any good society.
"According to The Elijah Price/Mr. Glass Principle, at least one actual infinity exists."
I know nothing about Mr Glass or Elijah, but the thesis is provable in set theory, provided you accept that the employment of axioms is inevitable in any science. It's known as the "axiom of infinity": For any natural number n, there exists at least one set with n members. At first glance, this doesn't look as if it had much to do with infinity. But perpend.
Let's say you choose the number 9. Well, there must exist at least the set of the numbers from 1 to 9, otherwise the number 9 would have no meaning. But if you have a set of 9 members, the total number of subsets formable would be 2^9; and from those you could form a further subset, with a cardinality of 2^2^9, and they would form a further subset... and so on ad infinitum.