Solution VS.T21 Robert Beezer

\begin{align*} \vect{u} &=\zerovector+\vect{u}&&\knowl{./knowls/property.Z.knowl}{\text{Property Z}}\\ &=\left(\vect{-w}+\vect{w}\right)+\vect{u}&&\knowl{./knowls/property.AI.knowl}{\text{Property AI}}\\ &=\vect{-w}+\left(\vect{w}+\vect{u}\right)&&\knowl{./knowls/property.AA.knowl}{\text{Property AA}}\\ &=\vect{-w}+\left(\vect{w}+\vect{v}\right)&&\text{Hypothesis}\\ &=\left(\vect{-w}+\vect{w}\right)+\vect{v}&&\knowl{./knowls/property.AA.knowl}{\text{Property AA}}\\ &=\zerovector+\vect{v}&&\knowl{./knowls/property.AI.knowl}{\text{Property AI}}\\ &=\vect{v}&&\knowl{./knowls/property.Z.knowl}{\text{Property Z}} \end{align*}