Proof of Theorem RREFU (Reduced Row-Echelon Form is Unique)

[kisonecat]

The proof of http://linear.ups.edu/html/section-RREF.html#theorem-RREFU is pretty long (and early in the course when students are anxious anyway).

A link to some sort of shorter argument like http://www.maa.org/programs/faculty-and-departments/classroom-capsules-and-notes/the-reduced-row-echelon-form-of-a-matrix-is-unique-a-simple-proof might be helpful, and might convey the idea that with time things get easier...

[rbeezer]

Thanks, Jim! I agree entirely, and it will be great to have a more compact proof. There is an outstanding Stack Exchange post I need to address about exactly this.