This is LaTeX code:
[latex]
\left\{ \left( 1,2,1,1\right) ,\left( 1,3,2,2\right) ,\left( 1,0,-1,-1\right) ,\left( 1,0,1,1\right) ,\left( 2,1,1,1\right)\right\}\\ \left( 1,0,-1,-1\right) =\alpha \left( 1,2,1,1\right) +\beta \left( 1,3,2,2\right)
[/latex]