In Group Project #2, in problem #8 where we are asked to prove the Shroeder-Bernstein Theorem, we are told to let f:A to B and g:B to A denote bijections. Can we do this? We don't know that such bijections exist. We only know that one-to-one functions from A to B and B to A exist. If we knew that such bijections existed, we'd already have proven that A~B and we'd be done with the problem before we started. Should the problem say instead that f and g are one-to-one functions, or is there some flaw in my logic?