> In upper-level courses, professors would work through one problem on the board for the entire class. Turns out, they'd do it wrong about half the time.
In my experience, such errors always were in the mechanical parts of the proofs, not in their main structure, and easy to spot and correct for the students, in the sense that at least one spotted them, and told the teacher.
In my experience, such errors always were in the mechanical parts of the proofs, not in their main structure, and easy to spot and correct for the students, in the sense that at least one spotted them, and told the teacher.