To:  Entire Course (Officially Enrolled Students Only), Teaching Staff  
From:  "Emily Riehl"  
Subject:  clarification  

In problem 6, "the rest" refers to the rest of the cube. So you are asked to prove that there is no move that would take a solved Rubik's cube and switch two edge pieces while leaving the rest of the cube as it is.

Just a reminder, my office hours tomorrow will be from 8-10pm in Lowell Dining Hall, so feel free to stop by with questions in anticipation of the midterm Wednesday.