- Bob and Alice decide to work on this week's homework together. Neither student has looked at the first problem yet. They come up with a sketch of a proof together, and then they each write up their own version of the complete proof. Alice states in her solution that she worked with Bob, and vice versa.
- Bob and Alice have both worked on the second problem, but they are somewhat stuck. Alice knows how to start, but she runs into trouble about halfway through the solution. She explains what she has done to Bob, and he figures out how to finish the problem. They then write up complete solutions separately, with Bob giving Alice credit for the first part of the argument, and Alice citing Bob for the second part.