The finite analogue come from the fact that infinity minus infinity is undefined, and can be anything from “still infinity” (like if you had infinity people and then only sent away the even numbered ones) to any number you choose, to negative infinity. In a finite problem, the answer becomes well-defined, but there are multiple possible answers.
The finite analogue come from the fact that infinity minus infinity is undefined, and can be anything from “still infinity” (like if you had infinity people and then only sent away the even numbered ones) to any number you choose, to negative infinity. In a finite problem, the answer becomes well-defined, but there are multiple possible answers.