Jim Fowler

Scalar multiplication associativity

2

In http://linear.ups.edu/html/section-VO.html, "Scalar Multiplication Compatibility" might be preferable to Scalar Multiplication Associativity, since there are two different operations involved.

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

1

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,...

Having things suddenly appear on the page can be disorientating for the reader.