/sci/ - Science & Math

>>11648362
>dude map the [math]i-th[/math] smallest element of [math]A \cup B[/math] to [math]i[/math] lmao
Proving this is a bijection is left as an exercise.

I don't think this is what your professor wants, tho, since it works for any unbounded subset of the naturals.

>>11592709
That's definitely a good part of it, but I feel like there's also something else. The political discussion last thread was absolutely horrendous, for example.