Suppose that $V$ is a vector space and $\vect{u},\,\vect{v}\in V$ are two vectors in $V$. Use the definition of linear independence to prove that $S=\set{\vect{u},\,\vect{v}}$ is a linearly dependent set if and only if one of the two vectors is a scalar multiple of the other. Prove this directly in the context of an abstract vector space ($V$), without simply giving an upgraded version of Theorem DLDS for the special case of just two vectors.